Case Title: Riley v. Commonwealth

Citation: 

Docket Number: 080920

State: virginia

Court: Virginia Supreme Court

Date: 2009-04-17T00:00:00Z

Document:
PRESENT:  All the Justices 
 
BRIAN PATRICK RILEY 
 
 
 
OPINION BY 
v.    
Record No. 080920 
JUSTICE CYNTHIA D. KINSER 
 
 
 
APRIL 17, 2009 
COMMONWEALTH OF VIRGINIA 
 
FROM THE COURT OF APPEALS OF VIRGINIA 
 
 
Brian Patrick Riley was convicted in a bench trial in the 
Circuit Court of the City of Alexandria of driving while 
intoxicated in violation of Code § 18.2-266 and maiming another 
person as a result of driving while intoxicated in violation of 
Code § 18.2-51.4.  The primary issue in this appeal is whether 
Riley met his burden to present evidence sufficient to establish 
the affirmative defense of unconsciousness predicated upon 
sleepwalking. 
Because the circuit court did not make a factual finding 
that Riley was sleepwalking at the time of the charged offenses, 
and because Riley's unconsciousness defense was predicated 
solely on the assumption that he was in fact sleepwalking, Riley 
failed to meet his burden to establish his unconsciousness 
defense.  Without that defense, the evidence established merely 
voluntary intoxication and was otherwise sufficient to sustain 
his conviction for maiming.  We will thus affirm the judgment of 
the Court of Appeals of Virginia upholding Riley's convictions. 
I. RELEVANT FACTS AND PROCEEDINGS1 
Riley drove his vehicle after admittedly ingesting three or 
four sleeping pills, an antihistamine, and a pain reliever.  
While driving, Riley struck and severely injured Paris 
Gebrekidan, hit two other vehicles, and then drove off the 
street onto grass, coming to a stop after striking a tree.  As a 
result of the accident, which occurred at approximately 7:00 
p.m. on January 27, 2006, amputation of Gebrekidan's left leg 
below the knee was required.  
Immediately prior to the accident, Hiwot Gebrekidan, the 
victim's sister, had parked her vehicle beside the victim's 
vehicle in order to transfer shopping items from one car to the 
other.  Hiwot turned on her hazard lights, and the two sisters 
exited Hiwot's vehicle to begin their task.  Moments later, 
Hiwot heard a "big sound" and observed her sister lying on the 
ground.  The accident took place at a dead-end street bordered 
by parked cars.  Hiwot testified that she did not hear any sound 
of braking before the vehicle struck her sister, and Officer 
Eric Lemke, one of the police officers who responded to the 
accident, testified there were no skid marks on the roadway 
leading to the point of impact. 
                     
1 We will recite the evidence presented at trial in the 
light most favorable to the Commonwealth, the prevailing party 
before the circuit court.  Gunn v. Commonwealth, 272 Va. 580, 
583 n.3, 637 S.E.2d 324, 325 n.3 (2006). 
2 
Hiwot identified Riley as the driver of the vehicle that 
struck her sister.  Hiwot testified that after the accident, she 
yelled for Riley, "asking where he was," but he did not respond.  
Instead, he followed Hiwot as she went to her apartment complex 
to seek assistance. 
Joseph Minasie, the victim's 15-year-old nephew, observed 
Riley after the accident and testified that Riley was "just 
standing there numb as if nothing happened."  When Minasie asked 
Riley whether he caused the accident, Riley first responded with 
statements that did not make any sense, but Riley finally 
admitted that he did, stating "it was just a chain reaction." 
Several police officers spoke to and observed Riley at the 
scene of the accident.  Officer Lemke noted that Riley was 
wearing sweatpants and a t-shirt despite the fact that it was 
30-35 degrees outside.  Officer Melvin Brooks testified that he 
observed Riley swaying back and forth and speaking incoherently.  
The officer asked Riley if he was the driver of the gray Honda 
involved in the accident; Riley responded incoherently, telling 
the officer "a friend of his had been driving his car earlier."  
The officer repeated the question, and Riley stated that he "was 
the driver of the vehicle in the accident, but [he did not] 
3 
recall what happened."  Riley also informed Officer Brooks that 
he had consumed "two shots of whiskey" and was a diabetic.2 
Riley acknowledged to Officer George Ladislaw that he was 
involved in the accident.  Pointing to the gray Honda involved 
in the accident, Officer Ladislaw asked Riley if the vehicle was 
his.  Riley said it was not his vehicle.  When asked where his 
vehicle was, Riley pointed to the other side of the street and 
stated his car was a "346" and "[i]t is either green or green."  
According to the officer, there was no such vehicle on the 
street. 
Because Riley appeared intoxicated, Officer Brooks 
administered field sobriety tests.  Officer Brooks explained 
each test to Riley, and Riley indicated that he understood the 
instructions and, according to Officer Brooks, "appeared to be" 
trying to follow the instructions. 
The officer administered four tests, the "alphabet test, 
the number count test, [the] finger touch . . . test and the 
one-legged stand test."  Riley's responses to the "alphabet 
test" and the "number count test" were erratic.  Riley refused 
to perform the "finger touch test."  Officer Brooks demonstrated 
the "one-legged stand test" to Riley.  The officer testified 
                     
2 The parties stipulated that another police officer also 
heard Riley state he was a diabetic.  They further stipulated 
that Riley is, in fact, not a diabetic. 
4 
that Riley, instead of standing on one foot and counting as 
instructed, "picked up his right foot off the ground and . . . 
put it right back down on the ground immediately and then . . . 
started walking forward."  Officer Brooks then placed Riley 
under arrest. 
Subsequently, Officer Brooks took Riley to a local hospital 
to have a blood test administered.  The results of Riley's blood 
test showed he had no alcohol in his system but had .04 mg. per 
liter of diphenhydramine, an antihistamine; .06 mg. per liter of 
propoxyphene, a pain reliever; and 0.56 mg. per liter of 
zolpidem, a sleeping pill.  
While at the hospital, Riley told two different officers 
that he had been drinking with friends at "Zig's Bar."3  Riley 
stated to one of the officers that he thought the accident 
occurred off Interstate 395.  When that officer tried to explain 
to Riley about the accident, Riley just stared at the officer.  
Riley told the other officer that he had been working in Front 
Royal that day and had returned home using Interstate 66 to 
Interstate 395.  When the officer informed Riley that those two 
highways did not intersect, Riley insisted he had taken this 
impossible route. 
                     
3 Officer Lemke found no evidence suggesting that Riley had 
gone to Zig's Bar on the night of the accident. 
5 
Riley's fiancée, Melanie Walck, who resided with Riley, 
testified that she spoke with Riley on the day of the accident 
at about 5:00 p.m.  According to Walck, Riley told her that he 
was going to have dinner and then take a nap until she arrived 
home.  When Walck arrived at approximately 10:30 p.m., she found 
the burners on the stove turned on, food on the kitchen counter, 
and plates on the table.  When she checked the bedroom to see if 
Riley was there, she found the bed disheveled, magazines on the 
bed, and the bedside light on.  She testified that Riley reads a 
paper or a magazine when he lies down to sleep.  She further 
testified that Riley always wears sweatpants and a t-shirt when 
sleeping and he would never leave the house dressed in his 
nightclothes or without his wallet and cellular telephone.4 
Walck could not find Riley in the apartment and became 
concerned that he was sleepwalking or had suffered a seizure 
because the circumstances were similar to those of a prior 
incident when Walck believed Riley had been sleepwalking.  After 
calling some friends who lived nearby, Walck learned about the 
accident and went to the scene, which was approximately a 
quarter mile from her and Riley's apartment.  Upon arriving, 
Walck met Officer Lemke and advised him that Riley's behavior 
was consistent with prior episodes when Riley had taken sleeping 
                     
4 When arrested, Riley had neither his wallet nor his 
cellular telephone on his person. 
6 
pills.  Walck also stated Riley had abused sleeping pills in the 
past, causing a problem in their relationship.  
Shortly after she arrived on the scene, Walck and Officer 
Lemke returned to her and Riley's apartment.  Walck retrieved 
from a briefcase several "blister packs" of medication, 
including "Ambien," "Lunesta," and "Sonata," as well as Riley's 
empty prescription bottle for Sonata. 
According to Walck, Riley has a history of seizures and 
sleep problems.  Walck testified that during her relationship 
with Riley, he rarely slept seven or eight hours until he 
received a prescription for Sonata.  Walck further testified 
that Riley previously had several episodes that Walck described 
as sleepwalking.  She explained that four of those episodes 
lasted about ten to fifteen minutes each during which Riley 
seemed "foggy" and talked to people who were not there.  Walck 
testified about three longer episodes that lasted up to three 
hours.  In one such episode, Riley got out of bed, went 
downstairs, turned on the stove burners, and started cooking 
food.  Walck stated that Riley eventually went back to bed and 
returned to normal sleep.  Riley never left the apartment during 
any of the episodes, and he had no recollection of them when he 
awakened. 
Riley also testified he had a history of epileptic seizures 
and was prescribed Sonata for sleep apnea.  The sleep apnea was 
7 
diagnosed when Riley underwent a sleep study; sleepwalking was 
not observed during the testing.  Riley acknowledged that he had 
also taken Ambien intermittently over the last five to six years 
but claimed he did not suspect his use of sleeping pills was 
associated with the episodes described as sleepwalking.  Riley 
admitted he was aware of the episodes and his bizarre behavior 
during them.  
He further testified that on the night of the accident, he 
did not intend to leave the apartment and was going to bed at 
5:00 p.m. for the evening.5  Riley stated he took "probably three 
pills" of Ambien, but admitted on cross-examination that "based 
on the testing . . . it's quite obvious[]" that he took at least 
four pills.  Riley claimed that he took more than one pill of 
Ambien because he wanted to be able to sleep and one pill would 
not have accomplished that purpose.  Riley remembered taking the 
Ambien pills and going to bed.  He stated that the next thing he 
remembered was being in jail. 
Riley acknowledged he did not have a prescription for 
Ambien but had obtained samples of the medication from doctors' 
offices and from colleagues who are pharmaceutical 
representatives.  Riley did, however, previously have 
                     
5 Riley testified he had no recollection of his conversation 
with Walck two hours before the accident during which he stated 
he was going to take a nap. 
8 
prescriptions for Ambien.  He admitted that when he was 
prescribed Ambien, the directions were to take one pill at a 
time, not to take the drug with other medications, and not to 
drive or operate any type of machinery.  Finally, Riley 
acknowledged that on the evening of the accident, he took 
"Benadryl and a prescription pain killer" along with the Ambien 
and that doing so was against his doctor's instructions. 
The Commonwealth called Dr. Joseph Saady, who qualified as 
an expert in the field of forensic toxicology and pharmacology, 
to testify concerning the results of Riley's blood test.  Dr. 
Saady testified that, according to the certificate of analysis, 
three substances were found in Riley's blood, "diphenhydramine," 
an antihistamine frequently sold under the trade name of 
"Benadryl"; "propoxyphene," a pain reliever usually sold under 
the trade name of "Darvon"; and "zolpidem," a sleeping pill sold 
under the trade name of "Ambien."6  According to Dr. Saady, the 
concentration level of the first two medications found in 
Riley's blood was the expected level if someone had taken a 
single dose of the medication.  Dr. Saady, however, testified 
that Riley had a concentration level of Ambien that was "rather 
excessive."  Dr. Saady opined that "a normal-size individual 
                     
6 Riley was taking Darvon for back pain related to a 
laminectomy he underwent in 2003.  The record does not indicate 
whether he had a prescription for this drug.  
9 
[would] have to take four [Ambiens] in order to achieve a .56 
[mg. per liter concentration level] about an hour to an hour and 
a half later." 
Dr. Saady explained that a patient is instructed to take 
Ambien just before going to bed because the medication takes 
effect on the individual in about 15 minutes and reaches it peak 
level of concentration approximately one hour after ingestion.7  
He further testified that an individual should only take Ambien 
if the person can get eight hours of sleep and even the next 
morning, the individual, in Dr. Saady's words, "should gain 
experience taking the drug before . . . operat[ing] machinery or 
do[ing] anything that requires extensive coordination and 
thought processes." 
Continuing, Dr. Saady testified that Ambien is 
"pharmacologically designed to induce sleepiness" but for an 
individual who is awake, the medication can cause drowsiness, 
confusion, somnolence, and coordination problems.  Somnolence, 
according to Dr. Saady, occurs when an individual becomes less 
interactive and quiet.  All these side effects, in Dr. Saady's 
opinion, would affect a person's ability to operate a motor 
vehicle.  Dr. Saady further opined that Riley's reported 
                     
7 According to the certificate of analysis, Riley's blood 
was drawn at the hospital at 8:35 p.m. on the night of the 
accident. 
10 
behavior on the night of the accident was consistent with an 
excessive dose of Ambien.  He stated that the antihistamine in 
Riley's system "would exacerbate" the effect of the Ambien 
because the antihistamine may also cause drowsiness. 
With regard to Riley's assertion that he was sleepwalking 
when the accident occurred, Dr. Saady testified it was "rare, 
but there are reports in the medical literature of individuals 
sleepwalking who have consumed" Ambien.  Dr. Saady further 
testified that he "could find no articles on sleep driving at 
all."  An article on sleepwalking, according to Dr. Saady, 
stated sleep driving could occur but was "very, very rare." 
Dr. Steven Brown, who qualified as an expert in sleep, 
sleep disorders, and sleepwalking, testified on behalf of Riley.  
Dr. Brown explained that sleepwalking "is an unwelcome[,] 
undesirable[,] involuntary and unpredictable intrusion of 
arousal . . . or a degree of wakefulness into the middle of 
sleep."  He opined that people who are sleepwalking engage in 
"[s]tereotypical activities" such as "cooking a meal, driving to 
work, [or] taking a shower."  According to Dr. Brown, a person 
who is sleepwalking will not offer spontaneous speech but will 
only speak when responding to questions. 
Dr. Brown further opined there are a number of triggers for 
sleepwalking, but they are unpredictable.  He stated a person 
could not be induced to sleepwalk, but a person is more likely 
11 
to sleepwalk if suffering from sleep deprivation for a long 
period of time or having irregular sleep habits.  He also stated 
"there are many medications which can trigger sleepwalking which 
is different than being impaired from medication." 
According to Dr. Brown, the hypnotic class of medications, 
which includes Ambien, can trigger sleepwalking.  Dr. Brown 
stated that an insert accompanying Ambien described sleepwalking 
as being a rare central nervous system side effect – rare 
meaning less than one in a thousand cases.  Dr. Brown also 
testified that there is no known correlation between excessive 
doses of Ambien versus a single dose in terms of its likelihood 
to trigger sleepwalking. 
In response to a hypothetical question, which was based on 
Riley's medical history, the events on the evening of the 
accident, and Riley's observed behavior after the accident, Dr. 
Brown opined that Riley was "sleepwalking at the time that he 
was driving his car."  He further opined that Riley's behavior, 
including the inability to answer questions, the blank stares, 
the incoherence, and the lack of memory, were consistent with 
sleepwalking.  Riley's prior episodes described as sleepwalking 
also contributed to Dr. Brown's opinion that Riley was 
sleepwalking on the night of the accident, rather than being 
merely intoxicated on Ambien. 
12 
Dr. Brown admitted on cross-examination that "sleep 
driving," as compared to other sleepwalking activities, is much 
less common.  He also acknowledged that ingesting an excessive 
amount of Ambien would interfere with a person's ability to 
perform field sobriety tests because the medication affects 
motor coordination and impairs memory.  Dr. Brown concurred with 
Dr. Saady's opinion that the concentration level of Ambien in 
Riley's blood was excessive. 
During closing argument for the defense, the circuit court 
inquired whether Riley would be immune from criminal liability 
"if he were sleepwalking."  The circuit court posed certain 
hypothetical questions, inquiring whether Riley would be 
criminally liable if he had set the apartment building on fire 
and killed twenty people or if he had killed his fiancé in a 
state of sleepwalking.  Riley's counsel responded that Riley 
would have absolutely no criminal liability for those actions, 
and the circuit court then stated, "Okay.  We understand each 
other."  When Riley's counsel claimed that Riley had previously 
engaged in sleepwalking, the circuit court declared, "It 
happened many times and he knew it happened and he knew he 
engaged in bizarre behavior when it did happen."  Also during 
closing argument for the defense, the circuit court expressed 
its belief that this was a case of voluntary intoxication, 
13 
stating, "He took an overdose of pills.  It certainly was 
voluntary." 
After the close of the evidence and hearing the parties' 
arguments, the circuit court rejected Riley's unconsciousness 
defense and found him guilty of both charges.  The court stated: 
The fact remains in this case the Defendant did 
have a long history of sleep disorders.  He had a long 
history of what has been described as sleepwalking.  A 
long history of bizarre behavior during those 
episodes. 
It is also I believe uncontested and clear that 
he took a significant overdose voluntarily of Ambien 
coupled with two other drugs.  One of which was an 
antihistamine that aggravated the effects of Ambien.  
There's medical expert testimony. 
I find that he either knew or should have known 
what the probable consequences were or if he didn't, 
taking voluntarily such an overdose of a drug which he 
certainly knew or should have known had a lot of side 
effects including sleepwalking if, in fact, he was, 
was in itself reckless disregard. 
For that reason, I'm satisfied the Commonwealth 
has proven its case.  [I f]ind the Defendant guilty of 
driving in a manner so gross, wanton and culpable as 
to show a reckless disregard of a human life and he 
did unintentionally cause serious bodily injury 
resulting in permanent and significant physical 
impairment. 
I likewise [find] him guilty of count two that he 
did operate a motor vehicle while under the influence 
of intoxicants. 
14 
At the sentencing hearing,8 the circuit court made the 
following additional remarks: 
Your crime, I believe, was indiscriminately 
taking an overdose of non[-]prescribed drugs, 
essentially having no idea what might happen, not that 
you knew it was happening, but you set in motion an 
indiscriminate act that had those consequences . . . . 
 
Riley appealed his convictions to the Court of Appeals, 
claiming the circuit court erred in rejecting his 
unconsciousness defense as to both charges and challenging the 
sufficiency of the evidence to sustain the maiming conviction.  
The Court of Appeals affirmed Riley's convictions in an 
unpublished opinion.  Riley v. Commonwealth, Record No. 2409-06-
4 (April 8, 2008).  Riley argued to the Court of Appeals he had 
established, as a matter of law, that because he was 
sleepwalking, he was unconscious, and thus could not be guilty 
of either offense.  Id., slip op. at 2.  The Court of Appeals 
rejected his argument, holding that the circuit court never made 
the factual finding that Riley was sleepwalking at the time of 
the accident.  Id.  Noting that the circuit court found this 
                     
8 On the maiming conviction, the circuit court sentenced 
Riley to two years in the penitentiary, all but six months of 
which was suspended for a period of four years on condition of 
supervised probation for four years.  The court sentenced Riley 
to twelve months in jail on the driving under the influence 
conviction.  The court suspended all but six months of that 
sentence under the same conditions, but with the additional 
condition that Riley complete the Alcohol Safety Action Program.  
The court ordered the sentences to run concurrently. 
15 
case was one of voluntary intoxication, the Court of Appeals 
concluded that the affirmative defense of unconsciousness was 
not available to Riley.  Id.  The Court of Appeals also 
concluded the evidence was sufficient to sustain Riley's 
conviction for maiming another person as a result of driving 
while intoxicated.  Id. at 5.  Riley now appeals to this Court. 
II.  ANALYSIS 
Riley assigns error to the Court of Appeals' holding that 
the circuit court did not find Riley was sleepwalking at the 
time he committed the charged offenses.  Next, Riley asserts the 
circuit court erred in rejecting his affirmative defense of 
unconsciousness as to both charges.  Finally, Riley challenges 
the sufficiency of the evidence with regard to his conviction 
for maiming another person as a result of driving while 
intoxicated.  We will first address Riley's unconsciousness 
defense and then consider the sufficiency of the evidence with 
regard to the maiming conviction. 
A.  Unconsciousness Defense 
This Court has defined the term "unconsciousness" as "a 
state of mind of persons of sound mind suffering from some 
voluntary or involuntary agency rendering them unaware of their 
acts."  Greenfield v. Commonwealth, 214 Va. 710, 714, 204 S.E.2d 
414, 417 (1974).  "Where not self-induced, unconsciousness is a 
16 
complete defense to a criminal homicide."9  Id.  Voluntary 
intoxication, however, is generally not an excuse for any crime.  
Swisher v. Commonwealth, 256 Va. 471, 488, 506 S.E.2d 763, 772 
(1998) (citing Wright v. Commonwealth, 234 Va. 627, 629, 363 
S.E.2d 711, 712 (1988)). "[T]he only exception to this general 
rule is in cases involving deliberate and premeditated murder."  
Id. 
When asserting an affirmative defense, such as insanity, 
self-defense, or unconsciousness, the burden is on the defendant 
to present evidence establishing such defense to the 
satisfaction of the fact finder.  Shifflett v. Commonwealth, 221 
Va. 760, 769, 274 S.E.2d 305, 310 (1981); see also Commonwealth 
v. Cary, 271 Va. 87, 99, 623 S.E.2d 906, 912 (2006) (recognizing 
that the burden of establishing the affirmative defense of self-
defense rests on the defendant); Commonwealth v. Sands, 262 Va. 
724, 729, 553 S.E.2d 733, 736 (2001) (same); Lucchesi v. 
Commonwealth, 122 Va. 872, 883, 94 S.E. 925, 928 (1918) (stating 
that the defendant had the burden to prove his affirmative 
defense).  In this case, Riley's unconsciousness defense was 
predicated on his assertion that he was in fact sleepwalking 
when the accident occurred.  Thus, Riley had the burden to 
present evidence, to the satisfaction of the circuit court 
                     
9 We assume, without deciding, that unconsciousness is a 
defense to criminal charges other than just homicide. 
17 
sitting as the fact finder, that he was sleepwalking at the time 
he committed the charged offenses. 
Contrary to the Court of Appeals' conclusion, Riley asserts 
that the circuit court did, in fact, find that he was 
sleepwalking at the time of the accident in question.  Pointing 
to the hypothetical questions posed by the circuit court and the 
circuit court's comments about Riley's history of sleepwalking 
episodes and his bizarre behavior accompanying those episodes, 
Riley asserts, "none of this discussion would have mattered if 
the court did not believe Mr. Riley had been sleepwalking."  
Riley also emphasizes the circuit court's statement during 
sentencing that "the worse case scenario did happen, not that 
you knew it was happening."  He asserts that if the circuit 
court did not believe that Riley was actually sleepwalking, the 
court would specifically have made such a finding and held that 
"Riley was in knowing operation of his vehicle."  We do not 
agree with Riley's position. 
Riley's argument overlooks the significance of the circuit 
court's final statements before finding him guilty of the 
charged offenses: 
I find that he either knew or should have known 
what the probable consequences were or if he didn't, 
taking voluntarily such an overdose of a drug which he 
certainly knew or should have known had a lot of side 
effects including sleepwalking if, in fact, he was, 
was in itself reckless disregard. 
 
18 
(Emphasis added.). 
This portion of the circuit court's ruling clearly 
indicates the court did not make a factual finding that Riley 
was sleepwalking.  The circuit court's statement, "if, in fact, 
he was" sleepwalking, negates any argument to the contrary.  At 
most, the circuit court made an alternative holding that if 
Riley was in fact sleepwalking, then his voluntary overdose of a 
medication he knew or should have known had side effects 
exhibited a reckless disregard for human life.  The comments 
made by the circuit court concerning Riley's prior history of 
episodes described as sleepwalking and the bizarre behavior that 
accompanied those episodes support the court's alternative 
holding. 
The hypothetical questions posed to defense counsel were 
exactly that, hypothetical questions; and they do not in any way 
establish the circuit court made a factual finding that Riley 
was sleepwalking.  Finally, the statement by the circuit court 
during the sentencing hearing that Riley did not know what was 
happening does not alter our conclusion.  A voluntarily 
intoxicated individual may not be aware of what is happening but 
would nevertheless be responsible for his conduct while in such 
a state.  See Chittum v. Commonwealth, 211 Va. 12, 17, 174 
S.E.2d 779, 782 (1970) (approving a jury instruction that 
stated, "A person cannot voluntarily make himself so drunk as to 
19 
become on that account irresponsible for his conduct during such 
drunkenness.  He may be perfectly unconscious of what he does 
and yet be responsible."); Gills v. Commonwealth, 141 Va. 445, 
450, 126 S.E. 51, 53 (1925) ("If a man voluntarily makes himself 
[intoxicated] he must take the consequences of his voluntary 
act, while [intoxicated], otherwise many crimes would go 
unpunished."). 
We thus hold that the Court of Appeals did not err in 
concluding that the circuit court made no factual finding that 
Riley was sleepwalking at the time he committed the charged 
offenses.  Riley, however, assumed that the circuit court did so 
and argued before the Court of Appeals he was entitled to an 
unconsciousness defense as a matter of law.  Because the circuit 
court did not make a factual finding that Riley was 
sleepwalking, the factual predicate underpinning his 
unconsciousness defense was missing.  In other words, Riley 
failed to meet his burden to present evidence, to the 
satisfaction of the circuit court, that he was in fact 
unconscious due to sleepwalking.  See Shifflett, 221 Va. at 769, 
274 S.E.2d at 310.  Therefore, his defense was reduced, as the 
circuit court recognized, to merely voluntary intoxication.  
It is well settled that voluntary intoxication 
furnishes no excuse for the commission of a criminal 
offense.  Swisher, 256 Va. at 488, 506 S.E.2d at 772 
20 
(generally, voluntary intoxication is no defense to any 
crime; the only exception being deliberate and premeditated 
murder); Wright, 234 Va. at 629, 363 S.E.2d at 712 (same); 
Director, Dep't of Corrections v. Jones, 229 Va. 333, 339, 
329 S.E.2d 33, 36-37 (1985) (voluntary intoxication is no 
defense to the crimes of robbery or use of a firearm while 
committing robbery); Griggs v. Commonwealth, 220 Va. 46, 
52, 255 S.E.2d 475, 479 (1979) (voluntary "intoxication, 
whether from drugs or alcohol, is no defense to a criminal 
charge"); Jordan v. Commonwealth, 181 Va. 490, 494, 25 
S.E.2d 249, 250 (1943) (voluntary intoxication, even when 
it may have "produced temporary insanity during the 
existence of which the criminal act was committed . . . 
would afford no excuse"); State v. McKeon, 38 P.3d 1236, 
1238-39 (Ariz. Ct. App. 2002) ("temporary intoxication is 
not a defense for a criminal act or requisite state of mind 
if it results from the abuse of prescribed medications"); 
People v. Turner, 680 P.2d 1290, 1293 (Colo. Ct. App. 1983) 
("where no controverting evidence is presented, a trial 
court would be correct in finding that excessive use of a 
prescription drug constituted voluntary intoxication"); 
Hicks v. State, 328 N.E.2d 219, 221 (Ind. Ct. App. 1975) 
(approving, as an accurate statement of law, a jury 
instruction stating that, "Temporary mental incapacity, as 
21 
a result of being under the influence of a narcotic or 
dangerous drug taken voluntarily and not on the 
prescription of a physician, furnishes no legal excuse for 
the commission of a crime" (internal quotation marks 
omitted)); Commonwealth, DOT, Bureau of Driver Licensing v. 
Lello, 571 A.2d 562, 563 (Pa. Commw. Ct. 1990) ("the person 
who exceeds his recommended dosage [of a prescription 
medication] is no different than the person who has had one 
drink too many . . . . In both cases there exists a 
situation where the prospective loss of mental and physical 
capacity was a foreseeable consequence when the driver 
undertook consumption." (internal quotation marks 
omitted)). 
Accordingly, and contrary to Riley's argument on 
appeal, the circuit court did not err in rejecting his 
unconsciousness defense.10  
B.  Sufficiency Of The Evidence 
Riley challenges the sufficiency of the evidence only with 
regard to his conviction for maiming another person as a result 
                     
10 We do not decide today whether a person who ingests 
medication in accordance with a doctor's or a manufacturer's 
instructions and then experiences some type of reaction, which 
could not have reasonably been anticipated and which renders 
that person unconscious or impaired, loses the unconsciousness 
defense or the intoxication defense because that person 
voluntarily ingested the medication. 
22 
of driving while intoxicated in violation of Code § 18.2-51.4.  
In reviewing the sufficiency of the evidence, "[w]e consider the 
evidence in the light most favorable to the Commonwealth, the 
prevailing party in the circuit court, and we accord the 
Commonwealth the benefit of all reasonable inferences deducible 
from the evidence."  Britt v. Commonwealth, 276 Va. 569, 573, 
667 S.E.2d 763, 765 (2008); accord Jay v. Commonwealth, 275 Va. 
510, 524, 659 S.E.2d 311, 319 (2008); Bolden v. Commonwealth, 
275 Va. 144, 148, 654 S.E.2d 584, 586 (2008). 
"When a defendant challenges the sufficiency of the 
evidence, we accord the judgment of a circuit court sitting 
without a jury the same weight as a jury verdict."  Britt, 276 
Va. at 573-74, 667 S.E.2d at 765 (citing Tarpley v. 
Commonwealth, 261 Va. 251, 256, 542 S.E.2d 761, 763 (2001) and 
Hickson v. Commonwealth, 258 Va. 383, 387, 520 S.E.2d 643, 645 
(1999)).  "We will affirm the circuit court's judgment unless it 
is plainly wrong or without evidence to support it."  Id. at 
574, 667 S.E.2d at 765 (citing Code § 8.01-680; Jay, 275 Va. at 
524, 659 S.E.2d at 319; Bolden, 275 Va. at 148, 654 S.E.2d at 
586; Tarpley, 261 Va. at 256, 542 S.E.2d at 763; and 
Commonwealth v. Taylor, 256 Va. 514, 518, 506 S.E.2d 312, 314 
(1998)). 
The statute under which Riley was convicted of maiming, 
Code § 18.2-51.4, provides in relevant part: 
23 
Any person who, as a result of driving while 
intoxicated in violation of § 18.2-266 or any local 
ordinance substantially similar thereto in a manner so 
gross, wanton and culpable as to show a reckless 
disregard for human life, unintentionally causes the 
serious bodily injury of another person resulting in 
permanent and significant physical impairment shall be 
guilty of [the maiming of another as a result of 
driving while intoxicated]. 
 
As the Court of Appeals held, this statute incorporates, by 
its terms, the culpability standard found in common law criminal 
negligence.  See Riley, slip op. at 4.  "Conduct that is 'gross, 
wanton and culpable' demonstrating a 'reckless disregard for 
human life' is synonymous with 'criminal negligence.' "  Jones 
v. Commonwealth, 272 Va. 692, 701, 636 S.E.2d 403, 408 (2006) 
(quoting Cable v. Commonwealth, 243 Va. 236, 240, 415 S.E.2d 
218, 220 (1992)).  "Criminal negligence is judged under an 
objective standard and, therefore, may be found to exist where 
the offender either knew or should have known the probable 
results of his acts."  Id.  (internal quotation marks omitted). 
This Court has defined criminal negligence in terms of 
gross negligence, stating: 
" 'Gross negligence' is culpable or criminal when 
accompanied by acts of commission or omission of a 
wanton or wilful nature, showing a reckless or 
indifferent disregard of the rights of others, under 
circumstances reasonably calculated to produce injury, 
or which make it not improbable that injury will be 
occasioned, and the offender knows, or is charged with 
the knowledge of, the probable result of his acts." 
 
24 
Cable, 243 Va. at 240, 415 S.E.2d at 220 (quoting Bell v. 
Commonwealth, 170 Va. 597, 611-12, 195 S.E. 675, 681 (1938)). 
The level of intoxication is "relevant to a determination 
of the degree of the defendant's negligence: whether ordinary, 
gross, or wanton."  Essex v. Commonwealth, 228 Va. 273, 283, 322 
S.E.2d 216, 221-22 (1984).  "It may serve to elevate the 
defendant's conduct to the level of 'negligence so gross, 
wanton, and culpable as to show a reckless disregard of human 
life.' "  Id. at 283, 322 S.E.2d at 222 (quoting King v. 
Commonwealth, 217 Va. 601, 607, 231 S.E.2d 312, 316 (1977)). 
We hold that the evidence was sufficient to convict Riley 
of maiming another person as a result of driving while 
intoxicated.  Riley voluntarily ingested an overdose of Ambien 
in conjunction with other medications, one of which enhanced the 
effect of the Ambien.  He did not have a prescription for the 
Ambien.  His blood test revealed an excessive amount of Ambien 
in his system indicating that he had ingested at least four 
times the regularly prescribed dose.  See Stevens v. 
Commonwealth, 272 Va. 481, 488, 634 S.E.2d 305, 310 (2006) 
(holding that defendant's high level of intoxication alone 
justified a finding that his conduct was gross, wanton, and 
culpable).  Riley admitted knowing that he was supposed to take 
only one pill of Ambien at a time and avoid driving or operating 
any type of machinery.  He also admitted that by taking the 
25 
Ambien along with an antihistamine and a pain reliever, he was 
violating his doctor's instructions.  Riley, in this intoxicated 
state, nevertheless drove his vehicle and struck the victim and 
two other vehicles before hitting a tree, all without any 
apparent braking.  The victim suffered serious injuries 
requiring the amputation of her left leg. 
After the accident, Riley failed several field sobriety 
tests.  Witnesses who observed Riley at the scene of the 
accident and at the hospital testified about his unusual 
behavior.  Riley could not accurately recall the events that had 
transpired subsequent to, and even prior to, ingesting the 
Ambien.  He did not seem to know what had happened or that he 
had caused the accident, and he gave bizarre responses to 
questions asked of him.  Dr. Saady testified that Riley's 
behavior after the accident was consistent with an individual 
who had taken an overdose of Ambien.  Further, Walck informed 
police at the scene of the accident that Riley's behavior that 
evening was similar to his behavior on other occasions when he 
had ingested sleeping pills.  
We hold that the circuit court's judgment was not plainly 
wrong or without evidence to support it.  See Code § 8.01-680; 
Britt, 276 Va. at 574, 667 S.E.2d at 765.  Riley's conduct on 
the evening in question was wilful in nature, "showing a 
reckless or indifferent disregard of the rights of others," and 
26 
was committed under "circumstances reasonably calculated to 
produce injury," or which made it "not improbable that injury 
[would] be occasioned," and Riley knew, "or is charged with the 
knowledge of, the probable result of his acts."  Cable, 243 Va. 
at 240, 415 S.E.2d at 220.  See also Stevens, 272 Va. at 488, 
634 S.E.2d at 310 (while the defendant's high level of 
intoxication alone justified a finding that his conduct was 
gross, wanton, and culpable, the fact that the defendant ran a 
red light, failed to apply his brakes before the collision, and 
did not know what he had struck were additional circumstances 
supporting the finding). 
III.  CONCLUSION 
For these reasons, we will affirm the judgment of the Court 
of Appeals upholding Riley's convictions for driving while 
intoxicated and maiming another person as a result of driving 
while intoxicated. 
Affirmed. 
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