State of Maine v. Derek S. Poulin, 144 A.3d 574

On October 23, 2012, Poulin’s grandmother was found murdered and her house set on fire; Poulin lived with her and his father. Physical evidence included numerous blunt and sharp injuries and petroleum distillates at the scene.
Investigators recovered clothing, a BMV receipt, a secondhand-store receipt, and a Google-Earth–formatted GPS download from a device in Poulin’s car suggesting the car was at/near the victim’s house until about 1:30 p.m., contradicting Poulin’s oral statement that he left around 11:30 a.m.
Seven handwritten notes allegedly by the victim describing disputes with Poulin were recovered; two dated notes were found by the victim’s purse, five torn notes were in the bedroom.
The State disclosed the GPS data to defense counsel only three days before trial and conceded the late disclosure violated automatic discovery rules; the State offered the data only for impeachment.
The trial court excluded the GPS data from the State’s case-in-chief but allowed it for impeachment if a witness testified inconsistently; it excluded all but a redacted dated note but said it would reconsider other notes if Poulin put the relationship at issue.
A jury convicted Poulin of murder and arson; Poulin appealed, arguing the discovery rulings and limiting-admission rulings violated his right to a fair trial.

Issue	Plaintiff's Argument (State)	Defendant's Argument (Poulin)	Held
Admissibility of late-disclosed GPS data	State: Data was automatically discoverable but disclosed late; should be excluded from case-in-chief but usable to impeach contradictory testimony.	Poulin: Late disclosure violated Rule 16 and the data should be excluded for all purposes; he was prejudiced and lacked time/expert to challenge it.	Court: Exclusion from State’s case-in-chief appropriate; admissible for impeachment if defense elicits testimony contrary to data; no fair-trial violation.
Admissibility of handwritten notes	State: Notes show victim’s intent to make Poulin move out, identity/motive, and relationship context; admissible (at least some notes).	Poulin: Notes are hearsay, unduly prejudicial, improper character evidence, and raise confrontation problems; should be excluded.	Court: Properly excluded except a redacted dated note; court may revisit admission if Poulin puts his relationship with victim at issue; no abuse of discretion or fair-trial violation.

Walder v. United States, 347 U.S. 62 (impeachment with otherwise excluded evidence permissible where defendant testifies inconsistently)
State v. Dechaine, 572 A.2d 130 (Me. 1990) (late-disclosed evidence may be used for impeachment)
State v. Landry, 459 A.2d 175 (Me. 1983) (good faith of prosecutor relevant to sanction selection; defendant may not use State’s breach as a shield)
State v. Mylon, 462 A.2d 1184 (Me. 1983) (trial court has broad discretion in discovery sanctions)
State v. Ledger, 444 A.2d 404 (Me. 1982) (discovery violation cannot deprive defendant of fair trial)
State v. Thurlow, 414 A.2d 1241 (Me. 1980) (purpose of discovery: reduce unfair surprise and allow merits-based adjudication)