Whittle v. State, 2013 Del. LEXIS 509

Whittle was tried on charges including Second Degree Murder, weapon offenses, and reckless endangerment, based largely on three witnesses: Biddle, Stewart, and Owens.
The State’s closing argument repeatedly stated that the witnesses were “right” or “correct,” allegedly shaping credibility of the three key witnesses.
Biddle testified Whittle fired a gun; Stewart testified inconsistently and did not clearly see a shooter; Owens testified he did not see a shooter and was high on heroin.
Physical evidence was limited: bullets suggested multiple shots with the same gun, but no firearm was introduced; ballistic trajectory was uncertain; no blood test on a shirt was performed.
The jury returned guilty verdicts, and Whittle appealed alleging improper prosecutorial vouching in closing.
The Delaware Supreme Court held the prosecutor’s vouching was plain error and reversed for a new trial.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Did the prosecutor improperly vouch for witnesses' credibility?	Whittle argues closing improperly vouched for credibility.	State contends inferences were supported by evidence and tied to the record.	Yes; improper vouching occurred.
Did the improper vouching rise to plain error under Wainwright v. State?	Whittle contends plain error given impact on fair trial.	State argues error, if any, does not meet plain error standard.	Yes; plain error established.

Wainwright v. State, 504 A.2d 1096 (Del. 1986) (plain error standard for prosecutorial misconduct)
Clayton v. State, 765 A.2d 940 (Del. 2001) (sua sponte intervention standard)
Baker v. State, 906 A.2d 139 (Del. 2006) (abandoned sua sponte intervention in favor of Wainwright)
Trump v. State, 753 A.2d 963 (Del. 2000) (prosecutorial comment guidance; avoid improper vouching)
Hughes v. State, 437 A.2d 559 (Del. 1981) (prosecutors cannot express personal opinions about credibility)
Small v. State, 51 A.3d 452 (Del. 2012) (prosecutorial vouching standards in closing)