Com. v. Atcheson, M.
2025 Pa. Super. 71
Pa. Super. Ct.2025Background
- Matthew Duane Atcheson was involved in a bar altercation in 2018, culminating in him stabbing Damen Dubrock after a series of escalating confrontations.
- Atcheson was charged with attempted murder, aggravated assault, simple assault, and recklessly endangering another person (REAP).
- Atcheson's trial strategy, under attorney Christopher Urbano, was to establish self-defense and raise doubts about his mental state using lay witness testimony.
- He was convicted on all charges and sentenced to 20-40 years; his direct appeal was unsuccessful.
- Atcheson filed a Post Conviction Relief Act (PCRA) petition alleging ineffective assistance of counsel for failing to adequately investigate and present defenses, specifically diminished capacity and related expert testimony on his supposed concussion.
- The PCRA court denied relief, and Atcheson appealed, focusing the appeal on the general failure to investigate and prepare a defense via expert evidence.
Issues
| Issue | Atcheson's Argument | Commonwealth's Argument | Held |
|---|---|---|---|
| Ineffective Assistance for Not Using Expert Evidence | Urbano failed to present an expert on his concussion to negate intent, weakening the defense. | Lay testimony was sufficient; expert wouldn't be admissible under controlling law. | No ineffectiveness; diminished capacity not a defense to attempted murder. |
| Applicability of Diminished Capacity Defense | Diminished capacity evidence should be used to mitigate mens rea for attempted murder and assaults. | The defense is legally unavailable for attempted murder or non-homicide specific intent crimes. | Diminished capacity is unavailable for the charged crimes. |
Key Cases Cited
- Commonwealth v. Sandusky, 203 A.3d 1033 (Pa. Super. 2019) (sets forth the test for ineffective assistance of counsel in PCRA context)
- Commonwealth v. Yaw, 305 A.3d 1068 (Pa. Super. 2023) (explains the requirements for diminished capacity defense and its limitations)
- Commonwealth v. Russell, 938 A.2d 1082 (Pa. Super. 2007) (diminished capacity not available for non-homicide specific intent offenses)
- Commonwealth v. Terry, 521 A.2d 398 (Pa. 1987) (psychiatric testimony admissible in first-degree murder cases only)