Man Pleading Guilty to Killing 18-Year-Old Soldier at Army Depot During Firearms Training

A man has been charged roughly six months after a firearms training session at an Army depot turned deadly.
The U.S. Attorney’s Office for the Middle District of Pennsylvania announced Monday that Sean Stark, 38, of Carlisle, Pa., was charged with involuntary manslaughter for allegedly killing U.S. Army Pfc. Krystofer Lopez, 18, on March 12 at Letterkenny Army Depot while conducting firearms training in a grossly negligent manner.
The office announced it has filed a plea agreement in which Stark agreed to waive the indictment and will enter a guilty plea at a future hearing date yet to be scheduled by the court. Stark was described by the depot as the LEAD Directorate of Emergency Services and has been suspended indefinitely.
“The death of specialist Krystofer Lopez during a training exercise on March 12, 2026, was a devastating tragedy,” Todd Wivell,
chief of public affairs at Letterkenny Army Depot, told Military.com. “Our thoughts and prayers remain steadfast with his family and unit.
“Letterkenny Army Depot has cooperated fully with federal authorities throughout this investigation. Because criminal proceedings are ongoing, we cannot comment further on the specifics of the legal charges or the case.”
The U.S. Army Criminal Investigation Division investigated the case while assistant U.S. Attorneys Scott Ford and Alisan Martin are prosecuting the case.
“The circumstances surrounding Mr. Lopez’s death are heartbreaking for his family and loved ones,” U.S. Attorney Brian Miller said in a statement. “I hope this prosecution brings some relief for the family while ensuring that justice is delivered.”
If convicted, Stark faces a maximum of eight years in prison, a term of supervised release following imprisonment, and a fine.
What Happened to Pfc. Lopez
Lopez was reportedly shot shortly after 9:30 a.m. in or near Building 322 on California Avenue, during his first day of firearms training at Letterkenny Army Depot in Pennsylvania, according to information provided to his parents by the Army’s Criminal Investigation Division and cited by local NBC affiliate WGAL.
Stark, a civilian police officer, was reportedly demonstrating how to use a SIG Sauer M17 pistol when the weapon fired and struck Lopez, killing him.
Carmen and Hector Lopez, the parents of the victim, told WGAL that Stark failed to comply with training protocols by not keeping his pistol unloaded while inside the facility.
When the shooting occurred that March morning, dispatch reportedly requested advanced and basic life-support units and initially described the incident as an accidental, self-inflicted gunshot during training. That account is purportedly different from what investigators later told the family.
Rescue Efforts Failed
At 9:37 a.m., dispatch classified the incident as a “class one” response that led to a medical helicopter request two minutes later. But after the helicopter had nowhere to land onsite, Lopez was transferred to a local hospital by ambulance.
Hospital records reviewed by WGAL indicated that multiple agencies performed CPR at the scene. Roughly seven minutes after the dispatch call, Lopez was in traumatic cardiac arrest. Responders reportedly continued chest compressions, attempting to control the bleeding while attempting to revive him.
An automated external defibrillator reportedly delivered one shock at 9:50 a.m. Nearly 20 minutes later, at 10:07 a.m., emergency personnel reported that Lopez had briefly regained a pulse when firefighters arrived. But he lost it shortly afterward.
Lopez was reportedly transported to Chambersburg Hospital and arrived at 10:18 a.m. without a pulse. Hospital records cited by WGAL described profuse bleeding from the gunshot wound, documenting more than 5,000 milliliters of blood loss.
Stark’s legal counsel issued remarks to WGAL.
“Our client, Sean Stark, and his family express their deepest condolences to the family of specialist Krystofer Lopez,” attorneys said in a statement. “The circumstances surrounding specialist Lopez’s unintentional death are tragic. These circumstances will undoubtedly be addressed at the appropriate times and in the appropriate venues.
“However, out of respect for specialist Lopez and his family, neither Mr. Stark, nor counsel will be making additional public statements in the immediate future.”
Lopez’s obituary said he was a 2025 graduate of Biglerville High School, where he excelled at wrestling. He was also an avid gamer, motorcycle enthusiast, enjoyed eating out at restaurants, and participated in charity bike runs.
“He always went above and beyond to help anyone he could, but most importantly, he always put his family first,” the obituary reads.





