State v. Sowell, 213 N.J. 89

Bonita Pitt visited defendant Sowell, an inmate, in a prison gym monitored by cameras; D’Amico observed a suspected drug transfer with Pitt leaning forward, kissing, and Pitt placing an item into Sowell's hand, later found in a bag of potato chips.
D’Amico radioed for seizure; the bag was recovered and contained a balloon with thirty decks of heroin; Roy Randolph conducted interviews after Miranda waivers by Pitt and Sowell.
Sowell and Pitt faced a three-count indictment for conspiracy, possession, and possession with intent to distribute heroin; the State introduced video and other proofs, including Sowell’s post-arrest admission.
The State presented expert testimony from Alfonso on heroin packaging, prison smuggling, and the value of heroin, based on a hypothetical outlining the transfer sequence.
Defense challenged the expert testimony as improper for a straightforward fact; trial judge instructed that expert opinions are not binding and the jury decides guilt.
Appellate Division affirmed the conviction but found some expert testimony improper; the Supreme Court granted certification to address the proper use of defense and gatekeeping in expert testimony.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether expert testimony on a straightforward transfer was proper	State: expert needed due to nuance of prison transfer.	Sowell: testimony usurps the jury; not beyond common understanding.	Some expert testimony was improper; not all, only the transfer opinion.
Whether the hypothetical used to elicit opinion was properly limited to trial facts	Expert based on trial facts and evidence already in record.	Hypothetical included non-ported facts; biased the opinion.	Hypothetical improperly included extra facts; limit to asserted evidence.
Whether experts may opine on guilt or credibility, or simulate legal conclusions	Odom allows some ultimate-issue testimony if properly framed.	Experts should not opine on guilt or mimic statutory language.	Experts cannot express guilt or credibility or legal conclusions; must avoid legal language.
Whether the gatekeeping role requires excluding unnecessary expert testimony	Expert testimony required for nuanced drug-transfer understanding.	Gatekeeping should bar opinion on straightforward facts.	Court endorses strict gatekeeping; bar the problematic transfer-hypothetical testimony.
Whether the error was plain error given overwhelming other evidence	If error occurred, other strong proofs could sustain conviction.	Admission of improper testimony could have altered verdict.	Error not plain; conviction affirmed as modified.

State v. Nesbitt, 185 N.J. 504 (2006) (gatekeeping; limit expert testimony to beyond common understanding)
Odom, 116 N.J. 65 (1989) (limits on expert opinions; can use hypothetical with caution)
Nesbitt, 185 N.J. 504 (2006) (cautions against using expert to state obvious facts)
State v. Baskerville, 324 N.J.Sup. 245 (1999) (jury could reach simple factual conclusions without expert aid)
State v. Summers, 176 N.J. 306 (2003) (allowing experts on roles in drug distribution when appropriate)