United States v. Habibi, 783 F.3d 1

Defendant Bahman Habibi was convicted in Oct. 2013 of possessing a stolen firearm in violation of 18 U.S.C. § 922(j); sentenced to 16 months plus 3 years supervised release.
The stolen police firearm was found hidden in a hole in the wall of Habibi’s basement after he led police to it on the day of the warrant.
Two of Habibi’s longtime heroin customers testified they and Habibi retrieved and hid the gun; they said Habibi carried it into the house and hid it.
Those witnesses also testified Habibi trafficked heroin and wanted to retain the gun as leverage in case of drug-related arrest.
Forensic testing showed DNA on the gun did not match Habibi; the government called an FBI agent to testify from his experience that handling items does not always leave detectable DNA.
Habibi requested a jury instruction on “transitory possession”; the district court refused, and the First Circuit affirmed the conviction.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Admission of evidence about Habibi’s heroin use/trafficking	Evidence was admissible to explain how Habibi came to possess the gun, show relationships with the retrievers, and show motive/intent	Evidence was unfairly prejudicial propensity evidence and exceeded Rule 404(b)/403 limits	Court: Evidence had "special relevance" (motive, context, course of dealing) and district court did not abuse discretion under Rules 404(b) and 403.
FBI agent testimony re: DNA residue	Testimony from agent about his experience was proper lay opinion to explain why absence of Habibi DNA was not dispositive	Testimony was impermissible opinion outside lay witness scope and should have been excluded under Rules 701/702	Court: Agent’s testimony was permissible lay opinion (701): based on perception/experience, helpful, not expert scientific opinion; no abuse of discretion.
Refusal to give a "transitory possession" instruction	N/A (proposed defense instruction)	Instruction unnecessary because record showed prolonged possession (gun retrieved Apr 25 and hidden until police found it June 14)	Court: Defendant failed to present sufficient evidence of fleeting contact; district court properly declined to give instruction.

United States v. Landry, 631 F.3d 597 (1st Cir.) (Rule 404(b) "special relevance" concept)
United States v. Doe, 741 F.3d 217 (1st Cir.) (test for evidence relevant apart from propensity)
United States v. Rodríguez-Berríos, 573 F.3d 55 (1st Cir.) (404(b) framework)
United States v. Gonyer, 761 F.3d 157 (1st Cir.) (distinguishing propensity use of prior bad acts)
United States v. Arias-Montoya, 967 F.2d 708 (1st Cir.) (prior acts as "course of dealing"/context)
United States v. Nai Fook Li, 206 F.3d 78 (1st Cir.) (deferential Rule 403 balancing)
United States v. George, 761 F.3d 42 (1st Cir.) (lay witness "on-the-job" expertise under Rule 701)
United States v. Valdivia, 680 F.3d 33 (1st Cir.) (bounds of permissible lay opinion testimony)
United States v. Ridolfi, 768 F.3d 57 (1st Cir.) (knowing possession—actual and constructive)
United States v. McLean, 409 F.3d 492 (1st Cir.) (constructive possession elements)