A 19-year-old man accidentally shot his girlfriend in her Mount Penn residence while playing with a semi-automatic handgun that had been modified into a fully automatic firearm, police said.

After the shooting Friday night, Isaiah Troche fled the home on Pennwyn Terrace, carrying a gun and parts in a bag that he ditched in a neighbor’s backyard, police said. He turned up a short time later at the Central Berks Regional Police Department on Perkiomen Avenue less than three blocks from his girlfriend’s home.

He was arrested and charged with aggravated assault, reckless endangerment, tampering with evidence, possessing a prohibited offensive weapons and carrying a firearm without a license.

Troche of the 200 block of Capri Lane, Maidencreek Township, was free on $25,000 bail following arraignment Saturday before District Judge Ann L. Young in Reading Central Court.

According to court documents:

Central Berks police were dispatched to the home about 7 p.m. for a report of a shooting, and 911 dispatchers relayed that the victim, a 19-year-old woman, was accidentally shot in the leg in her bedroom by her boyfriend. Further information relayed that the gun was placed inside a bag in the bedroom.

Sgt. Matthew Mace arrived and spoke to the victim before she was taken by an ambulance crew to a hospital. She said Troche was handling a gun when he discharged a round that struck her in the leg.

Mace noticed bullets on the dresser in the bedroom and blood spatter on the wall. He later learned that Troche fled the residence through a basement door, carrying a black bag that held the gun.

Officers searched the immediate area and found the bag underneath a cardboard box in a rear yard.

Detective Joseph Taimanglo opened the bag and found a .40-caliber Glock pistol, a 22-round extended ammunition magazine and a spent shell casing.

Affixed to the rear slide plate of the pistol was a device commonly referred to as a “switch,” which converts a semi-automatic pistol into a fully automatic firearm.

Taimanglo found two more Glock conversion devices in the bag. Family members told him that Troche is known to carry a gun in a black cross-chest-style bag.

The detective returned to the station and confronted Troche with the recovered bag and firearm. Troche admitted the bag belonged to him. He said he ditched it out of fear of legal consequences, referring to the conversion devices.

He inquired about the condition of his girlfriend and said he did not mean to shoot her.

He stated he was “playing with the gun and it went off,” Taimanglo wrote in the arrest affidavit.

Troche said he bought the gun from an unknown person in Reading, and Taimanglo found that no federal or state forms were completed for the firearm sale and transfer.

Information on the victim’s medical condition was unavailable.

The incident comes on the heels of an “urgent call to action” by Pennsylvania prosecutors, including Berks County District Attorney John T. Adams, for the state Legislature to pass a law specifically banning machine gun conversion devices. Local law enforcement personnel are increasingly seeing these devices in the hands of teenagers and young adults, he lamented.

While these devices are prohibited by federal law, local authorities in Pennsylvania can only charge someone caught with one of these devices under state law with possessing a “prohibited offensive weapon,” a misdemeanor.

“We need something with more teeth,” Adams said Tuesday.