A Shirley mother was indicted Monday on an upgraded charge of attempted murder after prosecutors say she intentionally ran over a teenager with a car, backed the SUV up and hit him again.

Suffolk District Attorney Ray Tierney says Jennifer Nelson, 35, hit a 15-year-old boy in the parking lot across from William Floyd High School in October.

"She decided to take the law into her own hands in really outrageous fashion," Tierney says.

Officials say Nelson believed the victim took part in a robbery that targeted her son earlier in the day.

The victim suffered six broken ribs, fractured his pelvis and had a punctured lung.

An investigation determined that the teen who was struck was not involved in the robbery.

Nelson is also accused of threatening a group of teenagers with a knife and a small bat.

Nelson was initially facing charges including reckless endangerment and assault.

Tierney says that the mother traded in her lease the evening of the incident to try to conceal evidence

If convicted of the attempted murder charge, she could face up to 25 years in prison.

Nelson went before a judge Monday and was released without bail despite prosecutors asking for $250,000 cash bail.

News 12 visited Nelson's home in Shirley for comment, but nobody would answer.