Filed 10/2/14 P. v. Chiclana CA2/1 NOT TO BE PUBLISHED IN THE OFFICIAL REPORTS

California Rules of Court, rule 8.1115(a), prohibits courts and parties from citing or relying on opinions not certified for publication or ordered published, except as specified by rule 8.1115(b). This opinion has not been certified for publication or ordered published for purposes of rule 8.1115.

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

SECOND APPELLATE DISTRICT

DIVISION ONE

THE PEOPLE,
Plaintiff and Respondent,

v.
MARCO CHICLANA,
Defendant and Appellant. B248015
(Los Angeles County Super. Ct. No. MA052518)

APPEAL from a judgment of the Superior Court of Los Angeles County, Lisa Mangay Chung, J udge. Affirmed. Alan Siraco, under appointmen t by the Court of Appeal, fo r Defendant and Appellant. Kamala D. Harris, Attorney General, Lan ce E. Winters, Senior Assistant Attorney General, Victoria B. Wilson, Supervising De puty Attorney General, and Mark E. Weber, Deputy Attorney General, for Plain tiff and Respondent.

——————————2 Marco Chiclana appeal s his felony convicti ons for battery inflic ting injury on a peace officer, resisting an executive officer, and resistin g, obstructing, or delaying a peace officer.
He contends there is insufficie nt evidence to suppo rt the convictions be cause the officer in question was not engaged in lawful performance of his duties. Appellant also maintains that the conviction for battery on a police officer causi ng injury must be revers ed or, alternatively,
reduced to a misdemeano r, because he was not the cause of the office r’s injuries, and the injuries were not suffici ently serious. Appellant also argues that the trial co urt erred when it permitted an expert witness to testify regarding use of force. Finally, appellant asks this
court to review the trial court’s in camera Pitchess 1 proceedings for proce dural improprieties. We conclude that substantial evidence suppo rts the convictions, the trial court properly
exercised its discretion to permit expert testimony , and that the court sa tisfied its obligations
under Pitchess . Accordingly, we affirm.
PROCEDURAL BACKGROUND By amended information, appellant Mario Chiclana was charged with offenses involving two members of the Los Angeles Sheriff’s Depart ment (LASD). As against Deputy Sheriff Jeremy Esswein, appellant was charged with battery inflicting injury on a peace officer (Pen. Code, § 243, subd. (c)(2); count 1), 2 resisting an executive officer (§ 69; count 2), and resisting, obstructing, or dela ying a peace officer (§ 148 , subd. (a)(1); count 10). As against Sergeant Justin Diez, appellant was ch arged with atte mpted mayhem (§§ 203, 664; count 3), assault on a peace officer (§ 245, subd. (c); coun t 4), resisting an executive officer (§ 69 ; count 6), and battery inflicting inju ry on a peace o fficer (§ 243, subd. (c)(2); count 9). Ap pellant pleaded not guilty. A jury trial was held. Over defense objections, the prosecution to introduced expert testimony regarding use-of-f orce. The jury found a ppellant guilty as char ged on counts 1, 2,

1 Pitchess v. Superior Court (1974) 11 Cal.3d 531.

2 All further statutory references are to the Penal Code unless otherwise indicated.3 6, 9 and 10. The jury found appellan t guilty of the lesser offense of battery (§ 242) as to count 3. Count 4, on which the jury was unable to r each a verdict, was dismissed. Appellant was sentenced to three years’ probation and concurrent sentences of 180 days in jail on counts 1 and 9. The court imposed a jail term of 180 days in jail for misdemeanor resisting arrest (count 10), to be served consecutively to the probation condition. As to counts 2 and 6, appellant was sentenced to serve three years’ probation. On count 3, the court impos ed and stayed a 180-d ay jail term under s ection 654. The court imposed various fees and fine s, and awarded appellant pres entence custody and conduct
credits.
FACTUAL BACKGROUND
Prosecution evidence On April 2, 2011, appellant’s father, Damaso Chiclana 3 , had just undergone heart surgery at the Antelope Valley Hospital in Lan caster (hospital). He in sisted on leaving the hospital before being released by his doctor. Af ter spending most of the day (April 2) at the hospital, appellant rece ived a call from a family friend, Ibarra DeLeon . DeLeon said Damaso was trying to leave th e hospital, and told appellant to return to the hospital. Appellant drove Damaso’s white Nissan Xte rra SUV, and parked in front of the hospital where he found Damaso sitting on a bench. Damaso had surgical drains in his legs, which were bleeding, and he was disoriented. Appellant tried unsuccessfully to convince his father to go back insi de the hospital. Instead, Damaso decided he would drive himself home,
climbed into the Xterra’s drive r’s seat, and tried to start the engine with one of several
screwdrivers in the cab. Appellant and his father got into a heated argument while Dama so was inside the Xterra, yelling and screaming at one another in Spanish. Appellant’s long-time friend, Louis Bozzo, who witnessed the exchange, testified th at appellant was the angriest Bozzo had ever

3 Appellant and his father share a surname. For the sake of clarity we will refer to appellant’s father by his first name.4 seen him. Appellant tried to take the screwdriver from his father. As they struggled for control of the tools, Damaso sc ratched appellant’s f ace with a screwdriver. The scratch was
small and looked like on e that might result from a finger nail scratch. Either Bozzo or appellant took the screwdrivers away from Damaso. Appellant’s wife called 911 for help after hosp ital security refused to intervene. She was “hysterical” while speaking with the dispatcher. Appellant’s wife told the dispatcher
several times that her husband ha d just been “s tabbed in the face with a screwdriver” by his father, whom she described as “5150.” When asked to describe the as sailant, appellant’s
wife said Damaso was Hispanic. She did not respond to the dispat cher’s request for a description of what Damaso was wearing. Disp atch put out a ca ll of a possible assault with a deadly weapon at the ho spital by an adult male Hispanic. Meanwhile, appellant had “given up” trying to reas on with Damaso. On the early ev ening of April 2, 2011, Deputy Es swein was alone on patrol in
Lancaster. 4 He wore his full unifor m and drove a black and white patrol car with lights on the roof and LASD insignias. Deputy Esswein was armed with a handgun, a baton, O.C. (pepper) spray, and a flashlight. He weig hed about 225 pounds. The patrol car was equipped with a “MDT” (mobil e digital transmitter), a small black box installed near the car’s floor, by the cent er of the front seat, th at displayed dispatched messages from a specific station. The MDT’s display screen was roughly two by four inches; approxim ately six to eight lines of text could be seen at one time . To view the MDT scre en, Deputy Esswein had to take his eyes off the road and look toward the floor in the middle of the car. Deputy

4 Deputy Esswein had been with the LASD since May 2007. Pr ior to b ecoming a deputy, he successfully completed 64 hours of use of force training at the academy. After joining the LASD, Deputy Esswein worked in the jail for about two- and-one-half years, before being assigned to patrol duty in Lan caster. As of April 2011 , he had about one-andone-half years experience as a patrol deputy. Deputy Esswein was trai ned to investigate and provide public safety in a situation like the one he encountere d at the hospital.5 Esswein also wore a tr ansmitter on his lapel through which he recei ved radio broadcasts from the LASD dispatch. At 5:01 p.m., Deputy E sswein, who was about a mile away, recei ved a radio
broadcast that a “245”—assault with a deadly weapon— had just occurred at the hospital. He sped toward the hospital with his lights and siren on. A moment later, dispatch broadcast updated information sayi ng a male Hispanic adult had st abbed the caller’s husband in the
face with a screwdriver. At 5:02 p.m., Deputy Esswein also recei ved an MDT message stating that a male Hispanic adult had stabbed the informant’ s husband in th e face with a
screwdriver. MDT and radio tran smissions sent at 5:03 p.m. reported that the suspect was standing in front of the hospital. At 5:04 p.m., an updated MDT message sa id the suspect was in side a white Nissan
Xterra. This transmi ssion came through at the same moment Deputy Esswein pushed the button on the MDT indicating he had arrived on sc ene, was getting out of the patrol car and would no longer be able to s ee the MDT. Deputy Esswein saw text on th e MDT referring to a Nissan Xterra, but di d not see the informati on regarding the suspect being inside the SUV. 5 Neither the MDT messages nor the radio di spatches prov ided the name or physical description of anyon e involved in the stabbing at the hospital, or their clothing. Deputy Esswein knew only that the suspect was an ad ult Hispanic man, who had “stabbed” the 911
caller’s “husband” “in the face wi th a screwdriver.” Having not seen the portion of the MDT transmission saying the suspect was inside the SUV, Deputy Esswein believed that person was “standing in front of the ho spital.” Because the purported victim had been stabbed in the face with a screwdriver, Deputy Esswein expected to encounter a violent situation involving “a lot of blood, a big ga sh, something along those lines.” He expected that, if someone had been “running around stabbing someone in the f ace,” it was likely some one else could also have been hurt, and that there would be at least one victim needi ng medical attention.

5 There had been no radio dispatch abou t the suspect being inside the Xterra.6 Deputy Esswein was the firs t officer to arrive. When he arrived, he saw a white Xterra parked in front of the hospital. An older man (Damaso) , was sitting in the driver’s seat of the cab, with the door open. Two pe ople (whom Deputy Esswei n later learned were appellant’s mother and DeLeon) stood near the drive r’s door talking to the man inside. A group of 10 to 15 people was gathered at the rear of th e SUV, behind which was parked a pick-up truck. Deputy Esswein did not know who the people were or whether they had anything to do with the 911 call. DeLeon was Hispanic, but Depu ty Esswein did not consider him a suspect. Depu ty Esswein approached the dr iver’s door and asked Damaso what had happened. Damaso responded in Spanish, but Deputy Esswein could not
understand what he said. As Deputy Esswein was speaking to Dama so, appellant approached Deputy Esswein “very aggressively . . . in a direct path” from the rear of the SUV. Appellant weighed
between 280 and 300 pounds. He was wearing dark, lo ose fitting, sweatpants and a hooded sweatshirt, and (as Deputy Esswei n believed at the time) had hi s hands in the pockets of his pants. 6 Deputy Esswein did not know who appellant was, and appe llant did not speak as he approached Deputy Esswein. Deputy Esswein described appellant’s facial expressions at that point variously as, “mad,” “angry,” “hostile , agitated” and “tense,” and said he carried himself as if he was “very agitated” and “ver y annoyed” at what was happening. Deputy Esswein was concerned that appellant might bethe suspected assailant . Appellant’s dark, baggy clothing made it difficult to see if was concealing a we apon. Appellant had a scratch
on one cheek. The scratch was red, but not act ively bleeding. It looked like br oken skin, or a surface wound one migh t receive if scratc hed by the finger nail of someone trying to push you away. It did not look like a bloody gash , or gaping stab wound . Deputy Esswein was
“nervous” and “scared.”

6 Surveillance video of the incident show n at trial shows that appellant’s hands were outside his pockets.7 Deputy Esswein took a step back, assumed a defensive position and asked appellant
about the scratch on his face. Appellant said his fa ther had stabbed him with a screwdriver. At that point, Deputy Esswein did not know Damaso’s id entity. To De puty Esswein, appellant’s hostile behavior wa s at odds with the minimal natu re of the scratch on his face and his aggressive approach. Deputy Esswein, who had past experience with suspects who falsely claimed to be victims, remained uncertain of appellant’s role in the incident at the hospital, and needed to continue his investigation and locate the screwdriver. Deputy Esswein told appellant to take his hands out of his pockets, asked if he had a weapon in his pocket or any outstanding warrants. Appellant took out his left hand and thrust the palm at Deput y Esswein, saying, “don’t even start with me.” As he continued to approach, appellant “bladed” his body, turning to th e side. His left side was closer to Deputy Esswein, and his right side was obscured. De puty Esswein did not see then that appellant had taken his right hand from his pocket. 7 Deputy Esswein testifie d that appellant’s stomach (appellant was obese) and the position of his body as he “b laded,” may ha ve obscured Deputy Esswein’s ab ility to see the right side of appe llant’s body. In Deputy Esswein’s experience, crime victims are usua lly cooperative, comp liant and anxious to tell their story. Appellant, by contrast, was “extremely resistiv e.” Deputy Esswein perceived appellant’s
words and manner as an “immediate threat.” He thought appellant migh t be the suspect and could have a screwdriver in his pocket. Deputy Esswein tried to grab ap pellant’s left wrist, to bend it behind appellant’s back. His intent was to ensure that appellant did not have a weapon, and to detain hi m while he investigated the stabbing. Deputy Esswein testified that, initially, he had not in tended to handcuff or arrest appe llant, and would not have employed force against him had he done as instructed. As De puty Esswein attempted to grab appellant’s left wrist, he pushed him against th e SUV to gain leverage. He told appellant to

7 Deputy Esswein acknowledge d at trial that surveillan ce video showed appellant had removed his hand from his right pocket. Deputy Esswein did not recall seeing the hand outside the pocket.8 take his hands out and put them behind his back. Instead, appellant wres ted his left arm from the deputy’s grasp, saying, “Fuck you. Get your fucking ha nds off me.” Deputy Esswein testified that appellant then pulled a yellow screwdriver from his right rear pants pocket and tried to hand it to someone nearby. At th at point, afraid a figh t was about to ensue, Deputy Esswein radioed for the “patch,” to aler t other deputies to the em ergent nature of the situation, and continued trying to ge t appellant’s hands behind his back. Appellant refused to comply. Instead, he pushed back, tried to turn around rather than facing the vehicle as instructed, twisted out of Deputy Esswein’s grasp and moved toward
the rear of the SUV. Severa l other people were close enough to touch Deputy Esswein. Deputy Esswein grabbed appellant’s left wrist again, told him to take his hands out and put them behind his back, and to st op fighting. Someon e yelled at Deputy Esswein to take his hands off appellant, and someone told appellant to stop fighting. Appellant’s wife, Bozzo and DeLeon were all yelling at Deputy Esswein, though he di d not hear what they were saying. The situation was te nse and compounded by loud noise from a helicopter by then circling above. When Deputy Esswein saw a ppellant pull the screwdrive r from his right pocket he tried unsuccessfully to knock it out of appellant ’s hand. Appellant eith er dropped the tool on the ground or passed it to another person. Depu ty Esswein “felt trap ped.” He was stuck between the SUV and truck, pe ople surrounded and were cursi ng at him. He was afraid whoever appellant had passed the screwdriver to might assault him. He tried taking appellant to the ground to gain control. Ap pellant escaped Deputy Esswein’s grasp and turned to face him, with his right hand ba lled into a fist. Deputy Esswein punched appellant in the face. Appellant, in turn, hit Deputy Esswein twi ce in the head with his fists. The two
men traded more blows. Sergeant Diez arrived as a ppellant and Deputy Esswein we re punching one another; Deputy Esswein was clearly losing the figh t. Sergeant Diez wore his LASD uniform and drove a black and white LASD Tahoe. He yell ed at appellant to st op fighting and tried unsuccessfully to place him in a Carotid rest raint. After jumping on appellant’s back,9 Sergeant Diez was able to pull him to the ground, as appellan t and Deputy Esswein continued punching one another, and Deputy Essw ein kneed appellant in the ribs. Appellant poked a finger in to one of Sergeant Diez’s eyes and said , “Get off me.” Ev en after he was on the ground, appellant contin ued to fight and resist , and tried to get up. Other deputies arrived to help. One deputy (Holm) used his flashlight to hit appellant on the right arm and in the rib cage or abdo men area two or three tim es. Another (Epstein) punched appellant in the rib cage or abdomen area as many as six times . A third (Foster) kneed appellant in the head, while a fourth (Carter) pressed his baton against appellant’s calves to prevent him from ki cking the other deputies. Throughout all this, appellant
continued to hit and resist the deputies. He yelled and cursed , refusing to comply with their commands to stop fighting and to put his hands behind his back. Appellant never assumed a defensive position (e.g., curling up in a ball), no r did he ask the deputies to stop hitting him. Instead, he continued engaging in offensive action against the deputie s. Finally, Deputy
Foster announced he wa s going to tase ap pellant, and did so. After appellant was tased, he said something to the effect of, “I’m done,” stopped resisting and laid on the ground allowing the deputies to put his hands be hind his back. No further force was used on appe llant. After being handcuffed, appellant apolog ized to the deputies, saying, “ I’m sorry. I’m stuck on stupid. I respec t you guys.” Appe llant told the deputies he was “suffe ring from a case of st upid,” and asked whethe r anyone was hurt. Later, inside the hospital, appe llant told Sergeant Diez (in Deputy Carter’s presence) that he was sorry, should not have punched the police officer, and that his “mind [was] st uck on stupid.” As a result of the altercation with appellan t, Deputy Esswein suff ered a swollen wrist, hand, and knuckles, and experien ced pain in his wrist that prevented him from moving it. His right arm was scratched, he had marks around hi s elbow. His face and left knee were swollen, and he ha d pain in his cheekbones where appellant punched him. Deputy Esswein
received medical trea tment for his injuries at the hospital. An X -ray taken of his wrist
revealed no broken bones. De puty Esswein did not receive any follow-u p treatment for his injuries. Sergeant Diez su ffered several small lacerations near one eye, in wh ich he also got10 appellant’s blood after appellan t jabbed his finger into it. A preliminary HIV test was negative, but Sergeant Diez underwent follow-up tests for six months to ensure there was no
infection. After the scuffle, one scre wdriver was found on the rear bumper of the Xterra, and another on the ground near by. A third tool, like a socket wrench, (also de scribed at trial as a screwdriver), was recove red from appellant’s le ft rear pants pocket after his arrest. The incident involving appellant and the deputies lasted about 90 s econds, and was recorded by a hospital surveillance camera. In July 2012, at th e conclusion of an in ternal affairs invest igation by the LASD,
which included review of the surveillance vide o, LASD’s internal affairs bureau concluded that Deputy Esswei n had sufficient time and should have seen that appellant ’s right hand was out of his pocket and not holding a weapon prio r to using force. De puty Esswein received a three-day suspension, he ld in abeyan ce until he complete d two courses on tactics and wrote

an essay. Defense evidence
Mario Sandoval On the evening of April 2, 2011, appellan t’s friend, Mario Sandov al, was working in the emergency room at the hospital and saw appellant lying on a gu rney. Sandoval went in and out of appellant’s room several times that night. He never heard appellant apologize or take responsibility for bringing on the altercation. Sandoval saw two or three deputies use cell phones to photograph appella nt. They were smiling and laughing outside appellant’s
room. Sandoval did not know what they were sa id or were laughing a bout. At least one deputy, whom Sandoval did not think had been invo lved in the scuffle wi th appellant, made
a motion as if to punch someone. Sandoval did not repo rt this behavior to anyone. Neither Deputy Esswein nor Sergeant Diez, who were being treated for cuts and bruises in the emergency room, partic ipated in the laughin g or punching motions, or take any photos.11 Courtney Overton On April 2, 2011, Cour tney Overton was a se curity guard at th e hospital. He saw appellant and Damaso argue outside the hospit al, saw blood coming down appellant’s cheek and told the family to call the LASD. Appellant had two screwdrivers in one hand. Overton saw Deputy Esswein arrive and speak with Da maso inside the Xte rra. Deputy Esswein walked toward appellant, whose hands were out and who held the screwdrivers in one hand. Appellant handed the tools to Deputy Esswein, and the two men shook hands. That was “when everything else happened.” Appellant was uncooperative, resist ed Deputy Esswein’s attempt to gain control of hi m and tried to pull aw ay. Deputy Esswein grabbed appellant’s hands to put them behind his back. As he did so, the crowd shouted at Deputy Esswein, with different people saying different things. Deputy Esswein did not tell ap pellant to take his hands out of his pockets; appellant’s hands were already out. The deputy pushed appellant against the SUV, and appellant pushed
back off the vehicle. Deputy Esswein punched appellant in the face. Overton did not see appellant clench his fists befo re Deputy Esswein sw ung at him. The two men wrestled with
one another. Overton did not see appellant throw a punch at De puty Esswein or any deputy. One deputy swung a flashlight at appellant, one kicked him and another kneed appellant. One deputy—Overton did not know if it was Deputy Essw ein—smiled while punching appellant repeatedly. Appellan t remained uncooperativ e until he was tased. Overton heard someone say, “you ne ed to stop,” as th e deputies tried to gain cont rol of appellant’s hands. A deputy tased appellant. Overton believed he saw at least se ven deputies use force against appellant. After appellant had been handcuffed, Overton saw deputies walking around the emergency room with arrogant, “puffed up” demeanors, as if they we re proud they had won a fight. Overton acknowledged it was possible the deputies were proudno deputy was seriously injured. He did not see a deputy take photo s of appellant. Steven Krinsky On April 25, 2012, Se rgeant Diez and other deputies appe ared at the Lancaster home of Steven Krinsky to conduct a parole compliance search for a Mr. Ta ylor. Krinsky refused12 them entry without a warrant. After Sergeant Diez explained no warrant was necessary, Krinsky let two deputies into hi s home, where they re mained for a couple of minutes before emerging without Taylor or anyone else. In late April a nd in July 2012, Kr insky registered complaints against Sergeant Diez with the LASD. In May 2012, Krinsky bought the internet domain “justindiez.com” and created a webpag e discussing how Sergeant Diez had violated his rights, and sent emails to Sergeant Diez. During cro ss-examination, an April 25, 2012 audio recording was played in which Krinsky said, “Y ou know, I no longer want to give you permission.” Krinsky was cross- examined about emails he sent to and a Facebook posting he made about Serg eant Diez, and a statement on his ju stindiez.com website regarding his willingness to testify a bout Sergeant Diez. 8 Krinsky did not witness the incident at the hospital on Ap ril 2, 2011.
Nikkia Wise On the evening of January 11, 2012, Deputi es Esswein and Fost er pulled up in a patrol car as Wise sat on her bike. Withou t saying anythi ng, Deputy Esswein pulled Wise off the bike, put her hands behi nd her back and put her on the hood of the patrol car. Both deputies held Wise’s hands behind her back. Deputy Esswein told Wise to get her hands higher. Wise told the deputies she had asthma and could not breathe. They asked Wise if she had any warrants; she had none and had never be en arrested or in tr ouble. Depu ty Foster put Wise in a headlock that ma de her choke. Wise tried to escape the headlo ck because she could not breathe. Both deputies tackled and handcuffed her. She hit the car, and suffered pain. When Wise said she could not breathe, on e deputy responded that she was fine if she could talk. They lifted Wise up and dragged her to the curb , where they held her down by pushing on her shou lders, causing her hoodieto choke her. Wise screamed. When two female deputies arrived Wise said she was screaming because she could not breathe. Deputies Esswein and Foster eased up on the pressure , allowing Wise to breathe, and the

8 During the prosecution case, Sergeant Diez testified abou t the search of Krinsky’s trailer and his subseque nt experiences with Krinsky, in cluding his effort to obtain a restraining order against him.13 female deputies searched her. Up to that point, neither Depu ty Esswein nor Deputy Foster told Wise why she had been stopped. While being searched, Wise was told she had been riding her bike at night without a light. Wise was released a nd given a ticket fo r not having a light on her bicycle or a valid identification. Wise carried a bus pass with her name and photo, which the fe male deputies found duri ng the search; Deputies Es swein and Foster did
not ask her about it. At the time of trial, Wise was su ing the LASD, Depu ties Esswein and Foster. She was repres ented by the same attorney repres enting appellant in a civil suit against the LASD. Wise does no t know appellant and was not a witness to the incident at
issue here. On cross-examination, Wise testified that Foster had treated her worse than Deputy Esswein. Deputy Esswein let Deputy Foster put her in a head lock, but also told Deputy
Foster to knock it off. Wise did not remember telling a female deputy that Deputy Esswein “really didn’t do anything.” Her primary compla int against Deputy Esswein was that he had pulled her off her bike for no reason, and did no thing when Deputy Fost er mistreated her. Wise has an unspecified mental disability. From A ugust 2011 to April 2012, Wise worked at Desert Haven, which employs disabled indivi duals who work in the community. She did cleaning work and folded towels before being terminated. Wise was af raid to work because she thought police officers were following and harassing her. Wise believed the police were still following her. The da y before she testified, Wise awok e at 4:30 a.m. to see 10 officers looking at her house from inside their patrol cars.
Several friends who had known appellant at least 10 years, and two neighbors,
testified as character witnes ses. They knew ap pellant to be a nonviolent person.
Prosecution rebuttal On January 11, 2012, Sergeant Andrea Bradley, then De puties Esswein and Foster’s supervisor, arrived at the locat ion where they had stopped Wise. Wise was sitting on the curb, handcuffed, yelling, “I am going to sue some cops. I can’t breathe. They are choking
me.” Wise did not seem to be having any trouble br eathing. Each deputy rested a hand on Wise’s shoulders, but ne ither appeared to exert any pressure on her shoulder s. Their hands14 were not close to her neck, and nothing appeared to be obstruct ing her throat. Wise declined medical assistance. Sergeant Bradley took Wise to a patrol car where Wi se cried, but did not seem to be in pain. After her release, Wi se took her bike and rode or walked away. On January 11, 2012, Wise s poke with a Lieutenant at th e Lancaster station about her experience. She said Deputy Esswein had not really done anything. The Lieutenant saw no bruising on Wise. DISCUSSION
1. The record contains substa ntial evidence to support appell ant’s convictions on counts 2, 10 and 1. Appellant contends the eviden ce is insufficient to support his convict ions on counts 2 and 10 for violating sections 69 and 148, respectively. He al so argues that his felony
conviction for violation of section 243 (count 1) must be reduced to a misd emeanor battery. a. Standard of revi ew and controlling law When determining the sufficiency of the ev idence to suppo rt a guilty verdict, “the relevant question is whether, after viewing the evidence in the light mo st favorable to the prosecution, anyrational trier of fact co uld have found the essential elements of the crime beyond a reasonab le doubt.” ( Jackson v. Virginia (1979) 443 U.S. 307, 319 [99 S.Ct. 2781, 61 L.Ed.2d 560].) “[T]he court must review the whole re cord in the light most favorable to the judgment below to determine whether it di scloses substantial evid ence—that is, evidence which is reasonable, credible, and of solid valu e—such that a reasonable trier of fact could
find the defendant guilty beyond a reas onable doubt.” ( People v. Johnson (1980) 26 Cal.3d 557, 578.) “‘Substantial evid ence includes circumstantial evidence and any reasonable
inferences drawn from th at evidence. [Citation.]’ [Citation.] We “‘“‘presume in support of the judgment the existence of every fact the trier could reasonably deduce from the evidence.’” [Citation. ]’ [Citation.]” ( People v. Clark (2011) 52 Cal. 4th 856, 943.) Section 69 prohibits knowingly resisting, by force or viol ence, a peace of ficer in the performance of his duty . (CALCRIM No. 2652.) Section 148, subdivi sion (a) prohibits the willful resistance, delay, or obstruction of a pea ce officer dischargin g or attempting to15 discharge his duty. (CALCRIM No. 2656.) A felony battery occurs if a pe rson willfully and unlawfully uses force or viol ence against a peace officer engaged in the performance of his duties, when the person knows or reasona bly should know the vic tim is a peace officer engaged in the perf ormance of his duties, and the officer is injured. (§§ 242, 243, subd. (c); CALCRIM No. 945.) Each crime requires proof the officer wa s acting lawfully at the time
the defendant resisted the officer. (See In re Manuel G. (1997) 16 Cal.4th 805, 815.) Traditional Fourth Amendment analysis di vides police interactio ns into three basic categories—consensual encounters , detention and arrest. Each category involves a separate analysis regarding the degree of restraint and extent to which a person is detained. ( People v.
Verin (1990) 220 Cal.App.3d 551, 555 , 557.) Unlike a consensual encounter or arrest, a lawful police detention must be “strictly limited in time duration, scope and purpose.” ( Id . at p. 555.) The agreed upon issue here is whether Deputy Es swein’s detention of appellant was
lawful. A detention of a person is a seizure within the meaning of the Fourth Amendment. ( People v. Souza (1994) 9 Cal. 4th 224, 229 ( Souza ).) A detention is lawful if the detaining officer can point “to specific artic ulable facts that, cons idered in light of the totality of the circumstances, provide some objective manife station that the pers on detained may be
involved in crimin al activity.” (Id . at p. at p. 231; United States v. Arvizu (2002) 534 U.S. 266, 273 [122 S.Ct. 744, 151 L.Ed .2d 740].) The circumstance s known or apparent to the officer must include specific facts which, viewed objectiv ely, would cause a reasonable officer to suspect both that crime-related activity has occurr ed, is occurring or is about to occur, and that the pers on to be detained is or was involved. ( People v. Conway(1994) 25 Cal.App.4th 385, 388 ( Conway ).) The officer must have a “reasonable suspicion” the person to be detained has violated the law. ( People v. Dolly (2007) 40 Cal.4th 458, 463) “‘Reasonable suspicion is a lesser standard than probable cause, and can arise from less
reliable information than re quired for pr obable cause . . . . [Citation.]” ( Ibid .) “The corollary to this rule is that an investigative detention predicated on circ umstances which, viewed objectively, support no more than mere curiosity, ru mor or a hunch is unlawful,”16 regardless of whether the offi cer acted in good faith. ( Conway , at p. 389.) Reasonable suspicion is measured by an objective stan dard, not a particular offi cer’s subjective state of
mind at the time of the detention. ( Id . at p. 388.) “Disputed facts relating to the question
whether the officer was act ing lawfully are for the jury to de termine when suchan offense is charged.” ( People v. Jenkins (2000) 22 Cal.4th 900, 1020.) A defendant’s subjective understanding that the officer’s conduct was lawful is not a required element of the prosecution’s proof. ( Id . at p. 1021.) “The touchstone of our analysis under the Fourth Amendment is always ‘the reasonableness inall the circumstances of the particular governmental invasion of a c itizen’s personal security.’ Terry v. Ohio [1968] 392 U.S. 1, 19 [88 S.Ct. 1868, 1878].” ( Pennsylvania v. Mimms (1977) 434 U.S. 106, 108–109 [98 S.Ct. 330, 332, 54 L.Ed .2d 331, 335].) The concept of reasonable susp icion cannot be reduc ed to a fixed set of rules; it must be determined by looking at “‘the totality of the circumstances—t he whole picture.’ [Citation.]” ( United States v. Sokolow (1989) 490 U.S. 1, 8 [109 S.Ct. 1581, 1585, 104 L.Ed.2d 1, 10].) This standard requires that a detention have only a “min imal level of objective justification” ( Illinois v. Wardlow (2000) 528 U.S. 119, 123 [120 S.Ct. 673, 675, 145 L.Ed.2d 570, 576] ), and may be initiated by an officer “basednot on certain ty, but on the
need to ‘check out’ a re asonable suspicion.” ( United States v. Clark (D.C.Cir. 1994 ) 24 F.3d 299, 303, citing Adams v. Williams (1972) 407 U.S. 143 , 145–146.) The offi cer’s conduct is judged in light of common sense and ordinary human experience, with deference accorded to
the officer’s abi lity to distinguis h between innocent and susp icious conduct. “[W]hen
circumstances are ‘“consistent with criminal activity,” they permit—even demand—an investigation . . . .’ [Citation.] A differe nt result is not warr anted merely because
circumstances known to an offi cer may also be “‘consistent with lawful activity.’” [Citation.] . . . ‘The po ssibility of an innocent explanation does not deprive th e officer of the capacity to entertain a reasona ble suspicion of criminal c onduct. Indeed, the principal function of [police] investigation is to resolve that very am biguity . . . .’” ( Souza , supra , 9 Cal.4th at p. 233.)17 b. Application
The sole issue is whether De puty Esswein’s initial detention of appellant was legally justified. As we shall ex plain, we conclude it was. As the nature of Deputy Es swein’s reasonable suspicions are circumstances relevant to our inquiry, we turn first to consider what a reasonable officer in his position would have suspected upon arri ving at the hospital. That suspicion would have been based on a synthesis of information from three sources: the MDT and dispatch communications, and the deputy’s ob servations at the scene. Here, MDT and radio tran smissions received before arrival, Deputy Esswein knew that an adul t male Hispanic had purportedly stabbed the
caller’s husband in the face with a screwdriver, and that the susp ect was standing in front of the hospital. At 5:04 p.m., as Deputy Esswein pushed the button indicating his arrival at the scene and exit from the patrol car, he saw part of a 5:04 p.m. MDT message referring to a Nissan Xterra. He did not notice another por tion of that message stating the suspected
assailant was inside the Xterra. As he pulled up, Deputy E sswein observed a group of people milling around a white Xterra. An elderly man sat alone inside th e SUV. He was disoriented, had drains in his legs and responded to Deputy Esswein’s inquiry about what was happening by saying something incomprehensible in Spanish. Deputy Esswein did not see that the man held a screwdriver, nor did he see such a tool near by. Nothing about Damaso’s demeanor or conduct gave Deputy Esswein reason to believe he was the assailant. At that point, there was a lone deputy, significantly outnumbere d by a crowd of people, who needed to investigate an urgent report that one unknown Hispanic man had stabbed another with a screwdriver, and no weapon was in sight. Just then, appellant, who matched the vagu e description of the suspected assailant, came from behind the Xterra. Appellant, wh o appeared angry an d hostile, and who outweighed Deputy Esswein by up to 75 pounds, moved for cefully toward the deputy. His clothes were baggy and prevented Deputy Esswein from seeing if he had a weapon. Appellant had an open cut on his cheek. Th e wound was red, and looked like a fingernail18 scratch, the sort of defensive mark one migh t receive from someone trying to fend off an attacker. Appellant said his father had st abbed him with a screwd river. Deputy Esswein did not know who appellant’s father was, a nd the abrasion did not look like the bloody gash the deputy would expect from a stab wound. Deputy Esswein had experienced situations in which a suspect falsely claimed to be a victim. The deputy proceeded with his investigation. Concerned by appellant’s confrontational behavior, Deputy Esswein asked him to remove his hands—obscured from view by th e size and position of appellant’s body— from his pockets, and whether he had any weapons or outstanding warrants. At that time Deputy Esswein did not intend to handcuff or arrest appella nt, only to ensure he had no weapons and to detain him on the curb while Deputy Esswein investig ated the assault. Rather than responding in the cooperative ma nner typical of a crime victim, appellant became “extremely resistive.” At that point, Deputy Esswei n suspected appellant was the assailant and posed an immediate threat to his and public safety . This suspicion gave rise to an urgent need to ensure that appellant had no weapons. Deput y Esswein attempted to do so and to get appellant’s hands behind hi s back. In response, appellant’s level of resistance escalated, and he angrily cursed at the deputy and twisted out of his grasp.
On these facts we conclude that Deputy Esswein had a particularized and objective basis to suspect that appellant was involved in criminal activity. Du ring the course of a detention, an officer may pat search a suspect fo r weapons if he “could ‘point to specific and articulable facts which, taken together with rational in ferences from th ose facts,’ would warrant the intrusion. [Citation.]” ( Souza , supra , 9 Cal.4th at p. 229.) Deputy Esswein justified the attempted search by the dangerous na ture of the 911 call, appellant’s angry demeanor and aggressive approach, his superior size and weight, baggy clothes, body position and refusal to comply. Appellant counters that, ev en viewed in tota lity, these facts do not support an objectively reasonable particular ized suspicion that he was engaged in criminal conduct or that he posed a threat to Deputy Esswein’s safety. Appellant argu es that key facts upon19 which Deputy Esswein relied were objectively erroneous, while others were merely the product of his subjective nervousness and impression of appellant’s demeanor. Deputy Esswein initia lly approached the incident and investigation relying on
inaccurate information that the assailant with the screwdriver wa s on the sidewalk outside the SUV. Relying on People v. Willis (2002) 28 Cal.4th 22, appell ant insists it was objectively
unreasonable for Deputy Esswein to persist in th is mistaken understanding. In Willis , the
issue was whether an of ficer’s good faith belief in the cons titutionality of a search pursuant to a warrant was objectivel y reasonable. The court held that an officer’s condu ct is unlawful
where the officer relies on false information from another member of a law enforcement agency, and that relian ce is objectively unreas onable because of fact s the officer knows or should have known. ( Id . at pp. 30–32.) First, appell ant maintains it was objectively
unreasonable for the dispatcher to mi stakenly report that the assailant was outside on the curb because appellant’s wife repo rted that Damaso was insidethe SUV. Second, it was objectively unreas onable for Depu ty Esswein to continue to rely on that erroneous information—by failing to read the full MDT transmission—after it was updated. Third, the dispatcher should have broadcast the updated informatio n by radio as we ll as by MDT. Regardless of whether the primary fault lies with the Deputy Esswein or with the dispatcher, appellant contends the deputy lacked an obj ectively reasonable basis to detain appellant. (See id

. at p. 45 [it was immaterial that erroneou s information on which officer relied was relayed by an agency clerk, as the clerk is an“integral part[] of the law enforcement team”].) Appellant also argues that, once at the scene, Deputy Esswein failed accurately to perceive that both of appellant’s hands were outside his pockets and on e was extended as he approached. Thus, Deputy Esswein proceeded to limit appellant’s freedom based on an unreasonably mistaken belief that appellant mi ght have a weapon in hand inside a pocket,
when available evid ence (as depicted at tr ial in the surveillance video and still photos made from each frame thereof) de monstrated otherwise. To accept these assertions would be akin to evaluating the integrity of a rope by separating its strands, then test ing each individual strand for it s tensile strength . This we will20 not do. Viewed in totality, the record cont ains substantial evidence from which the jury could reasonably have f ound that Deputy Esswein’ s decision to detain appellant was lawful. As the prosecutor noted at trial, even if Depu ty Esswein had seen the full MDT transmission about the suspect being inside the SUV, he could not be certain the suspect had remained there after the dispatcher relaye d that information. More importantly, as between the two Hispanic men in question, one elderly, disori ented, and apparently unarmed who sat inside the Xterra, and the other, with his hostile manner and aggressive approach, the deputy had a legitimate, objectively reasonab le concern that the latter wa s the suspected assailant. Accordingly, once Deputy Esswein left the patrol car to confr ont this scene, nothing about
his failure to have read the entire final MDT message would render his conduct unlawful.
Nor did the fact that di spatch first mistakenly reported th e suspect was standing outside. Deputy Esswein testified that hi s belief that the susp ect was outside was ju st one factor that concerned him. The pivotal factors were appellant’s appearance , hostile demeanor, aggressive actions and refusal to cooperate. With regard to his conceded failure to see appellant’s right hand, Deputy Esswein testified that, although he late r learned from the video that appell ant’s right hand was not inside his pocket, he wa s unable to see that at the time be cause of appellant ’s girth and body position. Deputy Esswein did no t decide to detain appellant merely because of an erroneous
belief that his hand was in hi s pocket. Within seconds of the time Deputy Esswein arrived and spoke to Damaso, ap pellant aggressively ap proached drawi ng the deputy’s attention to himself, and claimed the cut on his face was a stab wound. Based on his professional experience, the minimal nature of the scratch, and appellant’s level of hos tility, it was reasonable for Deputy E sswein not simply to ac cept at face value appell ant’s claim to be the stabbing victim. ( United States v. Arvizu , supra , 534 U.S. at p. 273 [“‘totality of the circumstances’” analysis “allows officers to draw on their own experience and specialized training to make infe rences from and deductions about the cumulati ve information available to them”].)21 Deputy Esswein acted in rapid response to appellant’s conduct and an uncertain, potentially dangerous situation, out of reason able concern for his own and others’ safety.
“The calculus of reasonableness must embody allowance for the fact that police officers are often forced to make split-sec ond judgments—in circ umstances that are tense, uncertain, and rapidly evolving—about the amount of force that is necessa ry in a particular situation.” ( Graham v. Connor (1989) 490 U.S. 386, 396–397 [109 S. Ct. 1865, 1872].) There is
minimal room for error when a police offi cer responds to a call invo lving an assault with a deadly weapon, and receives a confrontational reception. Even a car eful officer remains subject to attack. The “‘judici ary should not li ghtly second-guess a po lice officer’s decision to perform a pat down search for officer safety. The lives and safety of police officers weigh heavily in the balance of competing Fourth Am endment considerations . [Citations.]’ The Fourth Amendment has never been interprete d to ‘“require that police officers take unnecessary risks in the performance of their dutie s.” [Citation.]’” (People v. Collier (2008) 166 Cal.App.4th 1374, 1378; In re Richard G. (2009) 173 Cal.App.4th 1252, 1255.) People v. Mendoza (2011) 52 Cal.4th 1056 ( Mendoza ) is instruct ive. In Mendoza , the California Supreme Court held that a defendant’s hostile reaction to what began as a consensual police encounter, cons idered together with the facts that it was the middle of the night in an isolated area, and the officer wa s alone and outnumbered by three people, two of whom wore baggy cl othing loose enough to conceal weapons, ju stified the officer’s reasonable apprehension of da nger, and his decision to de tain defendant to check for weapons. ( Id . at p. 1082.) Here, as in Mendoza , supra , 52 Cal.4th 1056, there was su bstantial evidence from which a jury could reason ably find that Deputy Esswein ac ted lawfully to de tain appellant to check for weapons, and to isolate him and investigate his role in the incident at the hospital. Deputy Esswein arrived alone to investigate a reported assaul t with a deadly weapon, and was significantly outnumbered by a large group containing appellant, and his friends and family. Almost immedi ately (the enti re encounter lastedonly about 90 seconds), he was confronted by appellant —a much larger man than he—who behaved in an angry, hostile,22 uncooperative manne r. Both appellant’s c onduct and his appearance were inconsistent with his claimed status as the victim of a stabbing. The evidence shows th e decision to detain appellant at this point was part of the lone deputy ’s need quickly to locate a weapon and otherwise secure the scene in a developing situa tion. The detention was reasonable to ensure
the officer’s and others’ safe ty, and to enable him to conduct an investigation. (Id . at p. 1082; see also People v. Avila (1997) 58 Cal.App.4th 1069, 1072–1074 [officer had reasonable belief his safety was in danger where the defend ant acted suspiciously, walked around his car, dropped an envelope , and had a metal object within reach].) On this record, we are satisfied that Deputy Esswein’s decision to detain appellant was lawful, and the
convictions as to counts 2 and 10 stand. For the same reasons, we also reject appellant’s assertion that, because Deputy Esswein was not engaged in th e lawful performance of his duties, the felony battery conviction (count 1) should be reduced to a misdemeanor. 2. Substantial evidence suppo rts appellant’s felony convic tion for battery on a police officer causing injury Appellant also argues that the felony conviction for battery on a po lice officer causing injury (count 1), must be reve rsed because there is insuffic ient evidence that he caused Deputy Esswein’s injuries or that the injuries required medical treatment. a. Appellant as cause of injury
The court instructed the jurors that to prove appellant guilty of the crime of battery against a peace officer resulting in injury, the prosecution was requ ired to prove that: (1) Deputy Esswein was a p eace officer performing the dutie s of a deputy sheriff, (2) appellant willfully and unlawfully touche d Deputy Esswein in a harmful or offensive manner, (3) at a time wh en appellant knew or should have known that Deputy Esswein was a peace officer perfor ming his duties, (4) Deputy Esswein suffered injury as a result of that touching, and (5) appellant did not act in sel f-defense. (See CALCRIM No. 945.) The jury
was further instructed that harm ful “touching can be done indire ctly by causing an object or
someone else to touch th e other person.” The latter instruction reflec ts the principle that “cause” has a particular definition in crimin al law. (See CALCRI M No. 240 [An act or23 omission causes an injury if the injury is the direct, natural and probable consequence of the act or omission, and would not have happened without the act or omission].) Section 243, subdivision (c) im poses liability where “an injury is infl icted.” It does not require that the injury be willful ly or personally inflicted by the defendant. An injury may have one or more causes. An act or omis sion causes an injury if it was a substantial factor in causing the injury, i.e., something more than a trivial or remote factor. ( People v.
Caldwell (1984) 36 Cal.3d 210, 220.) Though Deputy Esswein did not know precis ely how he sustained his injuries, there can be no question that his injuries (swelling and lacerations on his hands, wrists and knees, and facial pain and bruising) resulted from the altercation set in motion by and involving appellant’s resistant conduct. It is sufficient that appellant willfully an d unlawfully touched Deputy Esswein, who suffered an injury as proximate result of that battery.
b. Victim need not r eceive medica l treatment Appellant also contends the conviction as to count 1 must be reduced to a
misdemeanor because there is no substantial evidence Deputy Esswein’s injuries required
medical attention.
As a result of the scuffle i nvolving appellant, Deputy Es swein suffered swelling in his face, knee, wrist, hand and knuckles. He suffered pain in his cheekbones from being punched by appellant, and was unable to move his wrist. The jury viewed photographs of Deputy Esswein’s injuries. Af ter the altercation, Deputy Essw ein spent several hours in the emergency room, where he was treated for cuts and bruises. An X-ray was taken of his wrist; it revealed no broken bones. “Penal Code section 243, s ubdivision (f)(6), de fines injury as fo llows: ‘“Injury” means any physical injury which requires prof essional medical treatm ent.’ There is no requirement in the statute the victim of the battery actuall y receive medical treatment. The language in subdivis ion (f)(6) merely defines the degree of the in jury. As wa s noted in People v. Longoria (1995) 34 Cal.App.4th 12: ‘It is the nature, exte nt and seriousness of the injury—not the inclination or disinclination of the victim to seek medical treatment—which24 is determinative.’ ( Id . at p. 17.) The inquiry is whether there is ‘sub stantial evidence from
which a rational trier of fact co uld have found [the officer’s] injuries required professional medical treatment.’ (Id . at p. 18.)” ( In re Michael P . (1996) 50 Cal. App.4th 1525, 1528- 1529, fn. omitted.) “The test is objective and factual.” ( Longoria, at p

. 17.) The standard of
review for this claim is the same as discussed in section 1, above.
In People v. Longoria , supra , 34 Cal.App.4th 12, the officer sustained an injury under section 243, subdivision (c)(1) af ter being kicked in the groin, sustaining cuts to his fingers
and the side of hi s hand, and his hand was crushed. Al though an X-ray take n of the crushed
hand revealed no broken bones, the officer was unable to hold his firearm and had to be placed on restrictive du ty for several days. ( Id . at pp. 15–16, 18.) Th e court found that a
“rational trier of fact could ha ve found that [the officer’s] in juries required professional medical treatment.” ( Id . at p. 18.) A simila r result was reached in People v. Lara (1994) 30 Cal.App.4th 658, 667–668, in which an officer was bruised on both knees , sustained cuts and abrasions on his hands, and was “exposed to de fendant’s blood.” Em ergency room medical personnel cleaned his wounds, ex amined him, treated contusions on his knees, and “gave him supplies for scrubbi ng himself later.” ( Ibid .) The court found this evidence sufficient to support a finding of in jury with in the meaning of section 243, subdivision (f)(6). ( Lara, at pp. 667–668.) In contrast with these cases, the court in In re Michael P. , supra , 50 Cal.App.4th 1525, on which appellant relies, he ld that a peace officer had not sustained an injury under section 243, subdivision (c), afte r being kicked by the defendan t in the chin and chest. ( Michael P. , at pp. 1528–1530.) At trial, th e officer testified that his chest and chin were sore from being kicked. He did not report the soreness to any medi cal personnel, no one wrote up an injury report or took photographs of hi s chest and chin, and there was no bruising. ( Id . at p. 1528.) The court r easoned that soreness alone was not an injury re quiring medical treatment. The battery statute in question measures culpability by the severity of an inflicted injury. Thus, the office r’s failure adequately to describe his injuries constituted a failure of evidence requiring reversal of the trial court’s finding of battery with in jury on a peace25 officer. ( Id . at pp. 1529–1530.) Wi thout injury the offense is a mi sdemeanor. (§ 243, subd. (b).) Here, Deputy Esswein sought and receive d medical treatment. He testified that he suffered swelling, lacerations, pa in and bruising. Be cause the significant swelling, pain and inability to move his wrist, emergency room medical staff deemed it necessary to X-ray Deputy Esswein’s wrist to see if it wa s broken. In re Michael P. , supra , 50 Cal.App.4th 1525 is factually disti nguishable from th e instant case, and does not assist appellant. 3. Expert testimony Appellant asserts that the j udgment must be reve rsed because the tr ial court erred in permitting expert testimony as to use of force. a. Factual background Over appellant’s objection, LASD Deputy Mark Caron testified as an expert witness regarding use of force. Depu ty Caron had been a deputy fo r over 22 years and, for the 11 years immediately preceding trial, was assign ed to work in field operations, or “force training.” Before that assignment, Deputy Ca ron spent five years on patrol, three of which
were as a field tr aining officer. He has ha d hundreds, if not thousand s, of encoun ters with people in the field. To beco me a use of force tr ainer, Deputy Caron ha d to complete three weeks of LASD training in a 120-hour st ate-approved course, and to attend a two-week
instructor’s course through the Lo s Angeles Police Department . In 2011, Deputy Caron attended the LASD academy in structors’ certification course . Deputy Caron’s unit was responsible for training new depu ties at the academy on all aspects of use of force, arrest and control. The LASD requires pa trol deputies to a ttend an eight-hour refresher course on use of force every two years, which is taught tw ice weekly by Deputy Caron and his unit. Deputy Caron also taught a three-week training course for in structors in his unit. Training
for all California peace officers is governed by the Pe ace Officers’ Standards and Training (POST), mandating a specific nu mber of hours for use of fo rce training. The LASD’s training satisfied POST requirements.26 At the academy, deputies are taught state and federal law regard ing appropriate and acceptable conduct, and arre st and control techniques (i.e., how to stand, make a fist, put on handcuffs and defend themselves). Deputies participate in three scenarios with an instructor which require the deputy to recognize and iden tify a threat, and choo se and employ the most appropriate force option. Typical ly, the scenarios involve one s ituation requiring little or no force, and two involving violent confrontations. Debriefing sessions follow each enactment. Deputies must also achieve a score of at least 88 on a mandatory written use of force test. Deputy Esswein could not have moved to patrol if he had not successfully completed the use of force courses and pa ssed the written exam. During training, de puties are taught they may encounter any of four categories of “cooperative,” “resistive,” “a ssaultive,” or “life threatening” behavi or. The deputy’s immediate perception determines the category into which a person’s behavior belongs, and the correspondingly appropri ate degree of force. No use of force need be employed in the first category of “cooperative” behavior, in whic h the individual complies with the deputy’s request or order. A deputy has the authority to searchand, in the event of safety concerns (e.g., the deputy believes the person may have a weapon), to handcuff. An individual will not necessarily be arrested simply because he or she is handcuffed. A deputy may handcuff someone as a precautionary m easure until the deputy ensures the person poses no threat.
“Resistive” behavior oc curs when a person physically or verbally opposes or defies a deputy’s direct command. A deputy has several options to deal with a resistive person. Using a firm grip, the deputy may position the pe rson in such a way that, assumi ng no further resistance, the deputy need use no additional force. If the person resists a nd the deputy must
overcome that resi stance, the latter action would be cons idered use of fo rce. A “control
hold” is a common option employed in such situations, in wh ich the deputy grabs the person’s arm and manipulates it into a wrist lock or arm contro l hold. An alternative option would be to spray pepper spray near (but not ai med directly at) the person. A third option is
referred to as an “intermediat e weapons control technique,” inwhich the deputy’s baton is27 used to assist in an arm contro l or arm lock. It may take more than one deputy to control a resistive person. In the third category of “assaultive” or “high risk” behavior, a deputy perceives a very real threat or high possibility of vi olence to himself or so meone else, because the individual is actually engaged in an assau lt on the deputy or so meone else, or the circumstances cause the deputy to believe that risk exists. One example of behavior which would fall into this category would be an encoun ter with a person who is clenching his fists, has tight jaw muscles, is shif ting his stance from neutral to blading his body, and putting his weight on the balls of his feet . Although this in dividual has not ye t assaulted anyone, circumstances cause the deputy to believe an assault may be imminent. The final category involves behavior by an individual which may be life threatening or cause serious bodily injury to the deputy or someone else. Seriou s injury includes such things as broken bones, concu ssions with loss of consciousness, skull fractures and bites. For this category, depu ties are authorized to use “personal” weapon s, such as punching, elbowing, kneeing or kicking the person. A de puty may use an “impact ” weapon, such as a baton or a flashlight, and a Carotid restraint is an authorized tactic at this level, as is the use of canines. “Less lethal munitions” may also be used. Those includ e firing a pepper spray ball at the person’s torso, tasi ng, or firing a bean bag or rubb er bullet at th e person. The tactic of “pain compliance” is us ed. That term mean s hitting a person so he or she will comply with the deputy’s orders and the inci dent can be ended as quickly as possible, denying a suspect anopportunity to escalate the dangerou s behavior. If a person is engaging
in behavior that is at the life threatening or serious injury le vel, deputies are trained that they may use a firearm or impact wea pon aimed at the pers on’s vital areas, incl uding the head and spine. Deputies are trained to hope for the best but to prepare for the worst. In other words, a deputy will approach a situation hoping the person will c ooperate, while at the same time remaining mentally and physicallyprepared to respond appropri ately in the ev ent the person engages in resistive or assaultiv e conduct. Deputies ar e trained to be sure that if they put28 their hands on a person, they are legally entitled to do so. They are also trained to think that
where “there is one we apon, there is another,” so that they must always conduct a thorough search even after a weapon is re covered. Deputies are also trained that if a fight is necessary, they must win. When a deputy is struck, death is a possibility. They are trained not to retreat once engaged in a fight, as th ere are inherent dangers to reli nquishing any level of control over the person. Th e aim is not just to hold a person down until the pe rson tires. The longer a use of force lasts, the greater th e risk of injury to the person and the deputy or deputies. So deputies are trained to gain safe control by getting the person handcuffed as quickly as possible.
In a situation in which a deputy encoun ters a group of peop le, does not know who among them is the suspect, and someone in th e group does so mething to make the deputy feel uneasy or threatened, deputies are trained to react as if that person is the suspect and to
control him or her and find out what is happening. They are trained to observe and consider peoples’ hands, facial expres sions, body language, degree of eye cont act, movements and what they say, and to err on the side of caut ion. Deputy Ca ron opined that, if a deputy believed someone posed a risk to him, the best practice would be to handcuff th e person, sort things out and, in the event the person posed no risk, re move the handcuffs. Responding to hypothetical ques tions premised on the facts of this inci dent, Deputy Caron opined that detention of a person in this situation would be appropriate, and that the deputies involved used appropriate levels of force und er LASD guidelines . It would be appropriate for a deputy to punch a person if the deputy believed the person was engaging in
assaultive conduct. It would be inappropriate for a de puty to hit a personwith a flashlight, tase, kick, knee or punch the person if he or she was not engaging in assaultive or the life threatening behavior.
The court instructed the jury to “consider evidence of the offi cer’s training and experience” in deciding wh ether appellant was lawfully detain ed. The jury was instructed on
the law about dete ntion, arrest and use of force. The court directed the jury to determine
whether the force used was objectively reasonable. Jurors were told they need not accept29 Deputy Caron’s expert opinion as true or corr ect, that they were fre e to disregard expert testimony they found unbelievable, unreas onable or unsuppo rted by the evid ence, and not to allow bias or sympathy to influence their decision. b. Legal standard Expert opinion is admissib le if it concerns a matter sufficiently beyond common experience and will assist the trier of fact. (Evid. Code, § 801, s ubd. (a).) Evidence Code section 801, subdivision (a) “doe s not flatly limit expert op inion testimony to subjects ‘beyond common experience’; rather, it limits such testimony to such subjects ‘ sufficiently beyond common experience that the opinion of an expert would assist the trier of fact ’ . . . . The jury need not be wholly ignorant of the su bject matter of the opinion in order to justify its admission; if that were the test, little expert opinion testimony would ever be heard. Instead, the statute decl ares that even if th e jury has some knowledge of the matter, expert opinion may be admitted wherever it would ‘assist’ the jury.” (People v. McDonald (1984) 37 Cal.3d 351, 367, overruled on another ground by People v. Mendoza (2000) 23 Cal.4th 896, 913; see People v. Stoll (1989) 49 Cal. 3d 1136, 1153–1154.) Applying this standard, California courts haveheld that a police officer may testify as an expert on techniques us ed to control arrestees ( People v. Singleton (2010) 182 Cal.App.4th 1, 21 ), and have considered opinion tes timony from experts on the issue of
reasonableness of force used by police in perf orming their duties (Lopez v. City of Los Angeles(2011) 196 Cal.Ap p.4th 675, 692; Brown v. Ransweiler (2009) 171 Cal.App.4th 516, 529–530; Munoz v. City of Union City (2004) 120 Cal.App.4th 1077, 1090–1093, disapproved on another ground by Hayes v. County of San Diego (2013) 57 Cal.4th 622.)
The decision whethe r to admit expert testimony is genera lly within a trial court’s discretion; such rulings are re viewed for abuse of discretion. ( People v. Manibusan (2013) 58 Cal.4th 40, 98.) Appellant argues Caron’ s testimony was irrelevant be cause, ultimately, it was the jury’s responsibility to determine whether Depu ty Esswein’s conduct (i .e., his use of force) was objectively reasonable. The latter point is not in dispute. Nevertheless, “‘[t]here is no30 hard and fast rule that the expert cannot be as ked a question that coincides with the ultimate
issue in the case.’ [Citations.]” (People v. Valdez(1997) 58 Cal.A pp.4th 494, 507.) Appellant also argues that Caron’s testimony and attend ant opinion that Deputy
Esswein’s conduct was consistent with LASD policy was irrele vant because it was premised on hypothetical fact s refuted by the re cord. The trial c ourt overruled appell ant’s objections to the prosecutor’s hypotheti cals. Those hypotheticals tracke d Deputy Esswei n’s testimony
and were consistent with the surveillance vide o. As discussed abov e, the fact that the dispatcher sent an MDT transmission saying the assailant was inside the SUV would not require Deputy Esswein to assume either that the suspect re mained inside the vehicle until he arrived, or that anyone he enc ountered in the vehicle would be the only possi ble assailant. Further, although the vi deo shows appellant’s right hand was outsid e his pocket, Deputy
Esswein testified that he was un able to see that at the time due to appellant’s size and the position of his body. Under th e circumstances, th e hypotheticals posed to Caron by the prosecution were proper. A hypothetical posed to an expert “‘“may as sume facts within the limits of the evidence, not unfairly assembled, upon which the opinion of the expert is required, and considerable latitude must be allowe d in the choice of fact s as to the basis upon which to frame a hypothe tical question.”’” ( People v. Vang (2011) 52 Cal.4th 1038, 1046.) Moreover, defense counse l posed a set of hypotheticals based on appellant’s view of the facts to Deputy Caron, who offered his opinion thereon as well. Finally, appellant maintains that Deputy Caron’s testimony should ha ve been
excluded because it was mo re prejudicial than probative (b ecause it focused the jury on the irrelevant question of whether Deputy Esswein complied with LASD policy, not whether the degree of force employed was lawful), and deprived him of due process. As reflected above,
the trial court instructed the jury regarding lawful detention, arrest and the use of force. The court’s instructions—to which appellant did not object—do not mention LASD policies. Further, the jury wa s instructed to ev aluate conflicting evidence, that it was free to accept or reject Deputy Caron’s expert opinio n, and that it should not let bias or sympathy influence its31 decision. We presume juro rs understood and followed the court’s instructions. 9 ( People v.
Pearson (2013) 56 Cal.4th 393, 414.) In sum, we conclude that Deputy Caron’s testimony was properly admitted, no t unduly prejudicial and its admissi on did not deprive appellant of
a fair trial. 10 4. The trial court fulfilled its responsibilities under Pitchess Before trial, appellant filed four motions under Pitchess . As relevant here, appellant sought complaints lodged against De puty Esswein, Sergeant Diez and eight other deputies for dishonesty and/or excessive use of force. The court found good cause to conduct in camera hearings as to Serg eant Diez, Deputy Esswein and seven other deputies. After its in camera review, the court ordered disclosure of certain discoverable
information. Appellant has asked this court to indepe ndently review for pr ocedural error the sealed transcripts of in camera proceedi ngs conducted on September 15 and 15, 2011, and July 16 and August 15, 2012, to determin e whether the court failed to make a proper
record of the materials it review ed and ordered disclosed. (Cf. People v. Gaines (2009) 46 Cal.4th 172, 180–181; People v. White (2011) 191 Cal.App.4t h, 1333, 1341–1342.) Respondent does not object.

9 The record reflects the jury, which sent out several notes during deliberation, knew it was free to seek clarification or guidance from the court if necessary. Further, to the extent appell ant failed specifically to object to Deputy Caron’s testimony regarding dangers faced by deputies, he forfeited th at argument on appeal. (See People v. Lindberg (2008) 45 Cal.4th 1, 48; Evid. Code, § 353, subd. (a) [in th e absence of a timely and specific objection, a judgment may not be reversed based on erro neous admission of evidence].)

10 Our conclusion that Deputy Caron’s te stimony was properly admitted and not unduly prejudicial defeats appellant’s argument that he was deprived of due process. (See Estelle v. McGuire (1991) 502 U.S. 62, 70 [112 S.Ct. 475, 481 , 116 L.Ed.2d 385, 398] [admission of relevant evidence does not viol ate due process unless the evidence is so prejudicial as to render the trial fundamentally unfair]; People v. Falsetta (1999) 21 Cal.4th 903, 913 [same]; accord, People v. Jones (2013) 57 Cal. 4th 899, 949.)32 The California Supreme Court in its decision in People v. Mooc (2001) 26 Cal.4th 1216, 1228 authorized appellate courts to review in camera Pitchess proceedings for error. During the in camera hear ing, the “trial court should then make a record of what
documents it examined before ruling on the Pitchess motion. Such a record will permit future appellate review. If the documents pr oduced by the custodian are not voluminous, the court can photocopy them and place them in a confiden tial file. Alternatively, the court can prepare a list of the documents it considered, or simp ly state for the record what documents it examined.” ( Mooc , at p. 1229.) The standard for review is an abuse of discretion. ( Id . at p. 1228; People v. Samayoa (1997) 15 Cal.4th 795, 827 [trial courts have wide discretion when ruling on motions to discover police officers’ personnel records].) We have independently reviewed the sealed reporter’s transcripts for the specified in camera hearings, and the trial court’s deci sion regarding the discoverability of material in the deputies’ personnel files. The transc ripts constitute an adequate record of the documents provided to and reviewed by the c ourt in those hearings. Based on our review of the court’s findings, we conclude the court fulfilled its responsibilities and properly exercised its discretion with regard to discovery denied. ( People v. Mooc , supra , 26 Cal.4th at pp. 1228–1229.) The trial court c onducted a diligent and thorough review of pertinent documents in the de puties’ personnel files before concluding that only certain evidence was properly discoverable evidence. There was no error.33 DISPOSITION The judgment is affirmed.
NOT TO BE PUBLISHED.

JOHNSON, J.

We concur:

CHANEY, Acting P. J.

MILLER, J. *

* Judge of the Los Angeles Superior Cour t, assigned by the Ch ief Justice pursuant to article VI, section 6 of the California Constitution.