State v. Christopher Gay, 145 A.3d 1066

Background

Late-night homicide: victim Ryan Stewart was found stabbed in his apartment building; bloody footprints and signs of struggle were outside and inside the unit.
Police reviewed surveillance video showing persons entering/exiting the building; officers suspected Christopher Gay based on prior encounters and a witness description of speech.
A bloodhound trailing "skin rafts" tracked a scent that led officers to Gay's residence; the dog briefly entered and explored the curtilage before losing the trail.
Shortly thereafter officers contacted Gay on his back porch/driveway; they asked him to show no weapon and questioned him for ~20 minutes; he was not arrested then.
Officers obtained search warrants for Gay's residence and person later that morning, executed them, and arrested Gay based on evidence recovered.
Gay was tried and convicted of second-degree murder and conspiracy to commit robbery; he appealed suppression denial, exclusion of alternative-perpetrator evidence, and admission of footwear-expert testimony.

Issues

Issue	Plaintiff's Argument (State)	Defendant's Argument (Gay)	Held
Warrantless canine entry onto curtilage	Exigent circumstances justified limited intrusion to follow a volatile scent trail in a homicide	Canine entry and sniff of curtilage was an unconstitutional warrantless search	Court: Exigency satisfied (scent disperses quickly; homicide gravity); limited intrusion reasonable — suppression denied
Detention in driveway	Officers conducted only an investigatory stop supported by reasonable suspicion	The driveway encounter was the functional equivalent of arrest, requiring probable cause	Court: Contact was an investigatory seizure, not custodial arrest; reasonable suspicion sufficient — suppression denied
Admission of evidence that a third party (Devon Smith) was alternative perpetrator	State: Proffered evidence lacked nexus and was impermissible other-bad-act or irrelevant hearsay	Gay: Evidence and statements linking Smith to incident were admissible to show alternative perpetrator and motive; exclusion violated confrontation/compulsory-proof rights	Court: Trial court reasonably excluded as insufficient nexus/relevance under Rule 404(b); cross-examination of co-defendant about inconsistent statements preserved; no Article 15 violation
Footwear-impression expert testimony	Expert could reliably testify that Gay’s shoes could have made prints (probative)	Expert’s methodology unreliable and testimony unhelpful because no positive identification	Court: Methodology reliable and testimony relevant as circumstantial evidence under Rule 702; admissible and weight for jury

Key Cases Cited

State v. Ball, 124 N.H. 226 (discussing warrantless entry and exceptions)
State v. Rodriguez, 157 N.H. 100 (exigent-circumstances analysis under N.H. Const. pt. I, art. 19)
State v. Santana, 133 N.H. 798 (foreseeability of exigency and limits on relying on expected exigency)
State v. Theodosopoulos, 119 N.H. 573 (reasonableness review of warrantless entries)
Terry v. Ohio, 392 U.S. 1 (investigatory stop vs. arrest standard)
Illinois v. McArthur, 531 U.S. 326 (state and federal search/seizure protections compared)
Daubert v. Merrell Dow Pharm., 509 U.S. 579 (expert-admissibility relevance and reliability framework)
State v. Roy, 167 N.H. 276 (application of Rule 404(b) to alternative-perpetrator evidence)
State v. Durgin, 165 N.H. 725 (nexus requirement for admitting alternative-perpetrator evidence)
State v. Dow, 168 N.H. 492 (trial court discretion on expert testimony admissibility)