GREENSBORO, N.C. -- It's been almost a year since 12-year-old Dorien Pearsall was killed in a hit-and-run crash in Greensboro and investigators still don't know who was driving the car, leaving Pearsall's family distraught.

"I just want to know why," says Trenise McKenzie, Dorien's mom. "Why didn't you stop?"

Investigators say Pearsall was hit by a car traveling south on Ward Road from East Market Street around 11:10 p.m. last Thursday. Pearsall was later pronounced dead at Moses Cone Hospital shortly before midnight.

Dorien attended Eastern Guilford Middle School and also played football at Peeler Rec Center.

Highway Patrol says the car struck the boy in the travel lanes and fled after the collision. The car involved is believed to be a dark blue BMW 7 Series. Troopers believe the vehicle is a 2003 to 2005 model and has damage to the passenger side with a missing right-side mirror.

His family just want whoever is responsible to come forward.

"It's been real tough," says Catrinia Hayes, Dorien's sister. "It was our first year we had to go through every holiday along, without him."

Hayes says Friday, February 16, they'll have a balloon release in Dorien's memory. It's set to start on Ward Rd. at 4:30. It's open to the public, who can bring their own ballons. That day will mark one year since the crash.

If you have any information that could help investigators, contact the N.C. State Highway Patrol at (336) 334-5500.