A Pennsylvania father will spend up to two years behind bars after his son picked up a loaded gun and fatally shot himself while in the 23-year-old man’s custody in June 2017.

According to the New York Post, Ryan Koch was sentenced this week after pleading guilty earlier this year to involuntary manslaughter.

His son, Bentley, died from what was described by police as an accidental shooting. The 4-year-old boy reportedly grabbed the firearm from a shelf in the Stroudsburg-area home where his father had left it after smoking marijuana.

Ryan Koch had full custody of the boy at the time of his death.

Police and emergency personnel responded to a home on Ash Lane near Brodheadsville on the day of the shooting, according to WNEP. The boy was transported to an area hospital where he was later pronounced dead.

Bentley’s mother spoke out in the wake of the sentencing hearing, calling her son’s death a “tragic accident” compounded by his father’s incarceration.

“It was difficult to watch,” she said. “He doesn’t deserve to go to jail.”

She said she did not want to see her ex locked up but conceded that “they had to do what they had to do.”

The father expressed remorse in a statement to his attorney, according to reports.

“If I didn’t have a gun in that house, I would still have my son,” he said.

After spending his one- to two-year sentence at Monroe County Prison, Koch will serve a three-year probated sentence.

[Featured image: Ryan Koch, video screenshot/Bentley Koch, Facebook]