On Tuesday, a Hummelstown, Pennsylvania police officer was charged with homicide in the shooting death of an unarmed man, The Associated Press reports. Officer Lisa J. Mearkle stands accused of shooting David Kassick, 59, twice in the back as he lay on the ground after a traffic stop.

From the AP's report:

Authorities said Mearkle had attempted to pull over Kassick for expired inspection and emissions stickers before he sped away. She caught up to Kassick near his sister's home where he had been living for a short time.

He got out and ran before Mearkle incapacitated him with a stun gun, held in her left hand. He was on the ground when she shot him twice in the back with the gun in her right hand, police said.

Mearkle, 36, told investigators she fired because he would not show her his hands and she thought he was reaching into his jacket for a gun. Perry said she did not know Kassick before the shooting.

A 15-year-veteran of the Hummelstown Police Department, Mearkle had never fired her weapon in the line of duty before, her attorney, Brian Perry, said at a press conference. "[Mearkle] did what she felt she had to do."

According to the AP, the arrest affidavit describes the video thusly: "At the time Officer Mearkle fires both rounds from her pistol, the video clearly depicts Kassick lying on the snow covered lawn with his face toward the ground... Furthermore, at the time the rounds are fired nothing can be seen in either of Kassick's hands, nor does he point or direct anything toward Officer Mearkle."

District Attorney Ed Marsico said that the stun gun contained a camera that recorded a 1.5-minute video of the incident. In it, the DA said, it appears that Kassick was trying to remove the stun-gun probe from his back. Marsico called the shooting death "a tragedy for all involved."

"Mr. Kassick is now dead as a result of a traffic stop, a routine traffic stop," one of the victim's family's attorneys, Christopher Slusser, said. "He should not be dead. He should not have died as a result of that traffic stop. And the manner in which he was shot—you can infer from that what you will."

Image via Shutterstock. Contact the author of this post: brendan.oconnor@gawker.com.