The civilian firearms instructor charged in the shooting death of an 18-year-old Army Reserve Soldier at Letterkenny Army Depot is himself an Army veteran who grew up in a military family with longstanding ties to the Carlisle area, an investigation by The Salty Soldier has found.
Federal prosecutors identified the instructor as Sean Stark, 38, of Carlisle, Pennsylvania, when they charged him last month with involuntary manslaughter in the March 12 death of Spc. Krystofer Lopez.
The Salty Soldier has identified Stark more fully as Sean Michael Stark, a former enlisted Soldier and the son of two retired Army officers.
The additional background provides a clearer picture of the man who eventually became a civilian law-enforcement officer and firearms instructor responsible for training personnel at Letterkenny.
That role is now at the center of a federal criminal case.
Prosecutors allege Stark killed Lopez while conducting firearms training in a “grossly negligent manner and with reckless disregard for human life.”
Two years before Lopez was killed, the Army publicly highlighted Stark’s role training Letterkenny police officers to respond to some of the most dangerous situations they could encounter.
An October 2024 Army article identified “Officer Sean Stark” as a Directorate of Emergency Services Law Enforcement, Security Division firearms and active-shooter instructor.
Stark conducted force-on-force active-shooter training that began in the classroom, moved to the range and eventually placed officers into simulated armed-threat scenarios.
Lt. Ronald Boughton, the division’s training officer, said Stark provided the experience and knowledge needed to prepare the officers, adding that his dedication to the training program contributed to the organization’s readiness.
Less than two years later, prosecutors say Stark was conducting firearms training when Lopez was fatally shot.
Lopez, an Army Reserve military police Soldier, was participating in training at Letterkenny on March 12 when he was struck in the chest.
The Justice Department has disclosed little about exactly what happened in the moments before the shooting. The criminal information states that Stark killed Lopez while carrying out an otherwise lawful activity — firearms training — but did so without the caution required for an activity capable of causing death.
Prosecutors allege his conduct was grossly negligent, showed reckless disregard for human life and created a danger Stark could reasonably have foreseen.
Lopez’s parents have provided a more detailed account.
They told WGAL that investigators informed them Stark had stepped outside the training area during a break, inserted a loaded magazine into his M17 pistol and later returned without clearing the weapon.
According to the family, Stark subsequently pointed the pistol at Lopez while demonstrating a training exercise and fired, striking the young Soldier in the chest.
The family has also said Army Criminal Investigation Division investigators told them the shooting was captured on video and that the M17 did not malfunction.
Those circumstances have not all been laid out publicly by prosecutors and remain, in part, based on the family’s account of what investigators told them.
Stark’s connection to the military predates his employment at Letterkenny.
He is the son of retired Army Col. Christine A. Stark, a career military police officer whose assignments eventually brought the family into the Carlisle military community.
Christine Stark attended the U.S. Army War College in Carlisle and later held positions connected to the War College and Carlisle Barracks. The family established itself in the Carlisle area during that period.
She spent more than three decades in the Army, with assignments that included Bosnia and Afghanistan, and rose to the rank of colonel.
Public family material reviewed by The Salty Soldier also identifies Sean Stark’s father, David, as a retired Army officer.
Before he became a civilian officer at Letterkenny, Stark served in uniform himself.
Publicly available family material reviewed by The Salty Soldier identifies Stark as an enlisted Soldier and places him in Army uniform years before his civilian law-enforcement career.
However, The Salty Soldier has not obtained Stark’s official Army personnel records and is therefore withholding any unconfirmed details about his specific MOS, deployment history, unit assignments or military decorations. The available evidence does, however, allow The Salty Soldier to confidently state that Stark previously wore the uniform himself.
Lopez was only 18 when he died.
A 2025 graduate of Biglerville High School, he had wrestled in school, volunteered with the Biglerville Fire Company and joined the Army while still a teenager.
He served as a 31B military police Soldier and was assigned to the 947th Quartermaster Company while participating in training at Letterkenny.
For months after his death, the Army publicly described what happened only as a “training incident.”
That description concealed the central fact that would later emerge: Lopez had been shot during firearms instruction.
Federal prosecutors did not announce a criminal charge until Sept. 21, more than six months after his death.
Stark was charged by criminal information with one felony count of involuntary manslaughter.
The government filed a plea agreement alongside the charge.
Under that agreement, Stark has agreed to waive indictment by a grand jury and plead guilty to involuntary manslaughter.
He has not yet formally entered the guilty plea in court.
That distinction is important. Stark has agreed in writing to plead guilty, but the plea must still be entered and accepted by the federal judge.
If convicted, he faces a statutory maximum of eight years in prison, along with supervised release and a potential fine. The plea agreement does not guarantee a particular sentence.
Army CID investigated the case.
Letterkenny has also acknowledged that Stark worked for the installation’s Directorate of Emergency Services and was suspended following the case.
Lopez was posthumously promoted to specialist.
Stark’s background does not determine his guilt. That will be decided through the federal court process.
But his history provides important context to the government’s allegation.
The person conducting the training that morning was not an inexperienced gun owner or someone unfamiliar with military firearms.
He was an Army veteran.
He was a civilian law-enforcement officer.
And he was the installation’s firearms and active-shooter instructor — a man the Army itself had publicly credited with providing other officers the knowledge and experience necessary to respond safely and effectively to armed threats.
Federal prosecutors now allege that while performing that same type of responsibility, Stark conducted firearms training so recklessly that an 18-year-old Soldier was killed.
For Lopez’s family, what was initially described publicly as a vague training accident has become something much more specific.
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