17-year old Tennessee boy unintentionally shoots sister while "joking" with it

A 17-year old boy in Collierville, Tennessee had been given a 9mm Luger handgun by his mother to "mess with", according to the boy.  He apparently was joking around with the gun, thinking it was unloaded because the clip had been removed, not realizing there was still a round in the chamber, when he discharged it, sending a bullet into his 15-year old sister's back, striking a lung and a rib, while she was on the couch with her boyfriend.

The mother had purchased the gun for self-defense after a break-in.

From the article:

The incident occurred Saturday on Fabert Cove in Halle Plantation in Collierville. Police said the teenager was holding Ward's 9 mm Luger when the gun discharged. His sister, who was lying on the couch near her boyfriend, was shot in the back. The bullet struck her lung and a rib. She was airlifted to the Regional Medical Center at Memphis.

She was listed in satisfactory condition and moved to a room Wednesday, according to Leslie Ballin, who is representing Ward.
....
Ward recently bought the gun after an attempted break-in at their home. She didn't think the police department responded fast enough, Ballin said. Police records don't show a report filed for that incident.

Ballin disputes the police report that said Ward told them she gave her pistol to her son "to play with" and to make sure the magazine was fully loaded.

The son told officers his mother gave him the gun to "mess with." He removed the magazine and believed the gun was cleared before it discharged, police records show.

The girl's boyfriend told officers that her brother was playing with the gun and "jokingly pointed the gun in their direction" when it discharged.

Every gun in the hands of a child must first pass through the hands of an adult.