IN THE SUPERIOR COURT OF THE STATE OF DELAWARE

STATE OF DELAWARE, )

 )

v. ) ID No. 2002007105

 )

TERRELL S. MOBLEY, )

 )

Defendant. )

Submitted: November 9, 2020

Decided: November 19, 2021

Upon Defendant Terrell S. Mobley’s Motion in Limine to Limit Expert Testimony

Regarding Firearm/Toolmark Evidence 

DENIED.

Upon Defendant Terrell S. Mobley’s Motion in Limine to Exclude Certain 

Convictions

DENIED.

OPINION AND ORDER

Matthew B. Frawley, Esquire and Periann Doko, Esquire, Deputy Attorneys

General, Department of Justice, 820 North French Street, Wilmington, Delaware

19801, Attorneys for the State.

Patrick J. Collins, Esquire, Collins & Associates, 8 East 13th Street, Wilmington, 

Delaware 19801, Attorney for Defendant Terrell S. Mobley.

WHARTON, J.
2

I. INTRODUCTION

Defendant Terrell S. Mobley (“Mobley”) is facing two first degree murder 

charges in separate indictments.1 Originally, the cases were specially assigned to 

two different judges, but upon the retirement of one of those judges, this judge was 

assigned to both. The older case, I.D. No. 1906003201, was assigned to the now 

retired judge, but was tried before this judge in August 2021. The jury was unable 

to reach a unanimous verdict and the Court declared a mistrial. Trial in that case 

now has been set for after trial in this case. There are two motions before the Court 

in this case, both submitted by Mobley: (1) a motion in limine to limit the opinion 

testimony of the State’s ballistic expert; and (2) a motion in limine to prohibit

impeachment of Mobley with certain prior felony convictions under D.R.E. 609 

should he elect to testify. The first motion in limine seeks to limit the opinion 

testimony of the State’s firearm/toolmark expert to preclude the expert from 

testifying to what Mobley believes is an unwarranted degree of certainty about his 

conclusions. The second motion in limine seeks to prohibit impeachment of Mobley 

with two prior felony drug offenses — Drug Dealing in a Tier 4 Quantity and Tier 4 

Possession of a Controlled Substance – should he testify. Mobley did not testify in 

his first trial, and he has not told the Court that he will testify in this trial. 

1

ID Nos. 1906003201 and 2002007105.
3

Nevertheless, because the option to testify remains open to him, the Court addresses 

the motion now so that Mobley may make an informed decision about testifying. 

The Court finds that the State has demonstrated by a preponderance of the 

evidence that the proposed expert opinion testimony is reliable. Therefore, 

Mobley’s Motion in Limine to Limit Expert Testimony is DENIED. The Court finds 

that the probative value of Mobley’s prior felony convictions outweighs their 

prejudicial effect and are admissible under D.R.E. 609(a). Therefore, Mobley’s 

Motion in Limine to Exclude Certain Prior Convictions is DENIED.

II. FACTUAL AND PROCEDURAL BACKGROUND

On April 3, 2018, the Wilmington Police Department responded to the 1400 

block of W. 3rd Street for reports of shots fired.2 Officers located the victim, Kevis 

Tyler (“Tyler”), suffering from gunshot wounds.3 Tyler was transported to 

Christiana Hospital where he died from his injuries — nine gunshot wounds.4 

Investigators recovered 28 spent 9mm shell casings as well as bullet fragments from 

the scene.5 This evidence was sent to the Delaware State Police Forensic Firearms 

Service Unit for analysis.6 Ballistics expert James Cadigan (“Cadigan”) concluded

2 State’s Resp. to Def.’s Mot. to Exclude Certain Prior Convictions, at 1, D.I. 17. 

3

Id.

4

Id.

5 State’s Resp. to Def.’s Mot. to Limit Expert Testimony, at 1, D.I. 18.

6

Id.
4

that all 28 casings were fired from the same firearm.7 Later, a firearm was recovered 

in an unrelated investigation.8 Cadigan concluded that gun fired all 28 casings.9 

Witness interviews pointed the investigation to Mobley.

10

 On February 17, 2020, 

Mobley was indicted on the charges of Murder First Degree, Reckless Endangering 

First Degree, Possession of a Firearm During the Commission of a Felony (two 

counts), Possession of a Firearm by a Person Prohibited, and Possession of 

Ammunition by a Person Prohibited.11 The latter two charges were severed on 

Mobley’s motion.12

On September 30, 2020, Mobley filed the motions in limine.

13 In support of 

the motion to limit expert testimony, Mobley argues that the State’s expert would 

mislead the jury by “testifying with any degree of certainty.”14 As to the motion to 

exclude prior convictions, Mobley concedes that his prior Burglary Second Degree 

conviction is admissible as proper impeachment under D.R.E. 609 as a crime of 

7

Id. at 2.

8

Id.

9

Id.

10 Id.

11 Indictment, D.I. 1.

12 D.I. 26.

13 Def.’s Mot. to Limit Expert Testimony, D.I. 14; Def.’s Mot. to Exclude Certain 

Prior Convictions, D.I. 15.

14 Def.’s Mot. to Limit Expert Testimony, D.I. 14.
5

dishonesty or false statement.15 But, he argues that his two drug-related felony 

convictions should be excluded as unfairly prejudicial.

16

III. THE PARTIES’ CONTENTIONS

A. Motion in Limine to Limit Expert Testimony

Mobley argues that the Superior Court, in State v. Gibbs,

17 already has held 

that firearm/toolmark examiners’ opinion testimony must be limited with respect to 

the degree of certainty of the match/identification.18 He argues this Court should 

follow Gibbs and other subsequent cases which allow the expert to state his 

methodology and opinion, but not to any degree of certainty.19 

The State argues that it has established repeatedly that the firearms and 

toolmark examination methodology satisfies all requirements for admissibility under 

D.R.E. 702.20 The State contends that Defendant can explore any possible issues 

with the expert’s degree of certainty through cross-examination, leaving it to the jury 

to determine what weight to give his opinion.21 

15 Def.’s Mot. to Exclude Certain Prior Convictions, at 3, D.I. 16.

16 Id.

17 2019 WL 6709058 (Del. Super. Ct. Dec. 9, 2019).

18 Def.’s Mot. to Limit Expert Testimony, D.I. 14.

19 Id.

20 Sate’s Resp to Def.’s Mot. to Limit Expert Testimony, D.I. 18.

21 Id. at 7.
6

B. Motion in Limine to Exclude Certain Prior Convictions,

Mobley argues that the drug convictions have minimal probative value on the 

issue of his credibility.22 In his view, this lack of probative value, coupled with a 

danger of unfair prejudice, weighs in favor of excluding those convictions, if he 

elects to testify in his own behalf.

23

 Mobley successfully advanced the same 

argument in his other murder case.

24

 Despite the favorable ruling, Mobley did not 

testify in that case. Nonetheless, he argues that holding is correct, and those 

convictions should be excluded in the trial of this case as well.

The State argues that Mobley’s convictions have probative value, especially 

considering their recency.25 Further, the State argues that Mobley’s history as a 

career offender is probative, and the drug convictions allow impeachment of his 

credibility without venturing into Mobley’s extensive “career as a felon.”26 The 

State contends that, under the balancing test set forth in D.R.E. 609(a)(1), the 

relevant factors suggest that Mobley’s convictions are highly probative of his 

credibility, and that the probative value outweighs any prejudicial effect.27

22 Def.’s Mot. to Exclude Certain Prior Convictions, at 5, D.I. 16

23 Id.

24 State v. Mobley, 2020 WL 2572738 (Del. Super. CT. May 21, 2010).

25 State’s Resp. to Def.’s Mot. to Exclude Certain Prior Convictions, at 8, D.I. 17.

26 Id. at 7.

27 Id. at 11-12.
7

IV. DISCUSSION

A. Motion in Limine to Exclude Expert Testimony Regarding 

Firearm/Toolmark Evidence

D.R.E 702 requires “the proffered testimony to provide relevant and reliable 

principles and terminology. This rule does not require that the conclusions derived 

from those principles and methods be scientifically valid. [T]he trial judge must 

determine that the expert ‘has a reliable basis in the knowledge and experience of 

the [relevant] discipline.’”28 The party seeking to introduce expert testimony bears 

the burden of establishing its admissibility by a preponderance of the evidence.29 

“[W]here the State’s expert testimony is based on methodology previously held 

reliable under Daubert, the State has demonstrated by a preponderance of the 

evidence that the proposed expert testimony is reliable.”30 

The methodology of the State’s ballistics expert witness has been held reliable 

previously under Daubert.

31

 However, Mobley suggests that current trends in case 

law point to limiting expert testimony in the area the certainty of the expert’s 

opinions.

32

 For example, the Court in Gibbs limited the State’s ballistics expert’s

28 McNally v. State, 980 A.2d 364 (Del. 2009). 

29 Bowen v. E.I. DuPont de Nemours & Co. Inc., 906 A.2d 787, 795 (Del. 2006). 

30 State v. Gibbs, 2019 WL 6709058, at *3 (Del. Super. Ct. Dec. 9, 2019) (citing 

McNally, 980 A.2d at 370)). 

31 State v. Phillips, 2015 WL 5168253, at *5-7 (Del. Super. Ct. Sept. 2, 2015) 

(quoting State v. McMullen, 900 A.2d 103, 114 (Del. Super. Ct. 2006)). 

32 Gibbs, 2019 WL 6709058, at *4 n.43 & n.44 (collecting cases). 
8

testimony where “‘the process by which a firearms examiner declares a ‘match’ 

remains inherently subjective,’ and where the State agrees that the expert is not to 

testify with ‘100%’ certainty...”33 Unlike in Gibbs, the State has not agreed to limit 

its expert’s testimony in this case. Because of the State’s agreement, the degree of 

the expert’s certainty in his opinion was not contested in Gibbs, diminishing Gibbs’ 

authoritativeness in this case when the issue is controverted.

 Neither Daubert, nor Phillips concerned themselves with the correctness or 

degree of certainty with which expert witnesses held their opinions. Instead, they 

were concerned with the reasonableness of the methodology by which the experts 

reached their opinions. Evaluating the weight to be given expert opinions, especially 

competing opinions, is manifestly a jury function. That is the reason why courts are 

concerned with the reliability of methodology rather than result in performing their 

gatekeeper function. The degree of certainty with which an expert holds an opinion 

may be warranted or not, but it is for the cross-examiner to exploit any 

overconfidence the expert might have in that opinion, and for the jury to adjudicate 

what weight to give it. The Court finds that the State has demonstrated by a 

preponderance of the evidence that the proposed expert testimony is reliable. 

Therefore, the Motion in Limine to Limit Expert Testimony is DENIED.

33 Id.
9

B. Motion In Limine to Exclude Certain Prior Convictions

D.R.E 609(a) provides:

For the purpose of attacking the credibility of a witness, 

evidence that the witness has been convicted of a crime 

must be admitted but only if the crime (1) constituted a 

felony under the law under which the witness was 

convicted, and the court determines that the probative 

value of admitting this evidence outweighs its prejudicial 

effect or (2) involved dishonesty or false statement, 

regardless of the punishment.” 

The State seeks to impeach Mobley with three prior felony convictions should 

he testify. The parties agree that his Burglary Second Degree conviction is 

admissible as impeachment evidence. That conviction occurred in 2005, but despite 

the 10-year time limit of D.R.E. 609(b), is admissible because Mobley was released 

from confinement on that charge less than 10 years ago.34 The other two felony 

convictions the State seeks to admit as impeachment are Drug Dealing and Tier 4 

Possession, both in 2016. Thus, the Court must balance whether the probative value 

of those convictions outweighs their prejudicial effect.35 If it concludes that their

probative value does outweigh their prejudicial effect, the evidence “must be 

admitted.”

36 But, only “the type of crime and the date and place of the convictions”

are admissible “without releasing the prejudicial details of the events.”37 “[T]he 

34 D.R.E. 609(b).

35 Gregory v. State, 616 A.2d 1198, 1203-04 (Del. 1992). 

36 D.R.E. 609(a).

37 Archie v. State, 721 A.2d 924, 928 (Del. 1998).
10

cross-examination should be restricted to the fact of the convictions, and the 

circumstances and details of the prior criminal conduct should not be explored by 

the prosecutors.”

38

 

Several factors can be considered when deciding the probative value of prior 

convictions: the recency of the conviction, where the crime falls on the scale of 

veracity-related crimes, and whether the crime was substantially different from the 

instant prosecution.39 The Court in United States v. Hayes noted that a conviction 

for “mere narcotics possession” would have less probative value than either selling 

or smuggling.40 In this instance, Mobley both sold and possessed narcotics, which 

still are relatively low on the scale of veracity-related crimes.41 However, the 

convictions are relatively recent—both occurring in 2016—and they are 

substantially different in character from the crimes charged here.

42

 

D.R.E. 609 recognizes that the fact of a felony conviction, no matter what the 

charge, has inherent impeachment value. If the State were limited to impeaching 

Mobley with the 2005 burglary conviction, the jury would be presented with a 

distorted view of his testimonial credibility, since it might reasonably conclude that 

38 Id.

39 U.S. v. Hayes, 553 F.2d 824, 828 (2d. Cir. 1977). 

40 Id. at 829 (citing United States v. Ortiz, 553 F.2d 782 (2d Cir. 1977)). 

41 See id.

42 Id.
11

it should give little impeaching weight to a conviction occurring a decade and a half 

ago. The relatively recent convictions present the jury with a more comprehensive 

basis to assess Mobley’s credibility. Mobley’s recent past convictions for narcotics 

offenses do not create a substantial risk that the jury would draw the forbidden 

character inference that Mobley acted in conformity with a character predisposed to 

murder.43 The crimes are substantially different. Thus, the Court concludes that the 

probative value of Mobley’s two felony drug convictions outweighs their prejudicial 

effect. The Motion in Limine to Exclude Certain Prior Convictions is DENIED.

44

THEREFORE, Defendant Terrell Mobley’s Motion in Limine to Limit

Expert Testimony Regarding Firearm/Toolmark Evidence is DENIED.

43 Id. (Finding that “[t]he conviction was for a crime substantially different from the 

instant prosecution, so that there was not here the prejudice to appellant that 

inevitably results from the introduction of a conviction for the same crime as that for 

which he is on trial.”)

44 The Court appreciates that it has reached a different conclusion than the judge in 

Mobley’s other murder case. State v. Mobley, 2020 WL 2572738 (Del. Super., May 

21, 2020). In addition to weighing the probative value and prejudicial effect

differently, the Court reaches a different conclusion for two other reasons. First, it 

appears the judge in that case applied the standard for balancing admission of 

convictions older than 10 years under D.R.E. 609(b) which requires the probative 

value of admission be supported by “specific facts and circumstance.” Id., at *1.

D.R.E. 609(a) contains no such requirement. Second, and more importantly, her 

determination that drug convictions generally are “highly prejudicial when offered 

to impeach the veracity of a witness whose innocence or guilt is being determined 

by the jury,” was based on Gregory v. State, 616 A.2d 1198, 1203 (Del. 1992). Id. 

In Gregory, the impeaching drug convictions were offered to impeach the defendant 

who was on trial for drug charges. Obviously, the prejudice was much greater in 

that case because it had character and propensity implications under D.R.E. 404(b) 

not present here. See, Hines v. State, 248 A. 2d 92 (Del. 2021). 
12

Defendant Terrell Mobley’s Motion in Limine to Exclude Certain Prior 

Convictions is DENIED.

IT IS SO ORDERED.

/s/ Ferris W. Wharton

Ferris W. Wharton, J.