CHICAGO (CBS) — A Morton Grove woman has filed a lawsuit against the city of Carbondale, the city’s police chief, and the man she believes killed her 19-year-old son in February.

WBBM Newsradio’s Steve Miller reports the wrongful death lawsuit filed in Jackson County alleges a man who gave 19-year-old Pravin Varughese a ride beat him to death. The suit seeks at least $1 million in damages.

Varughese, a sophomore at Southern Illinois University, went missing on Feb. 12 after leaving a party in Carbondale. He was found dead nearly a week later.

An autopsy determined he died of hypothermia, but his family was convinced someone killed him, and paid for a second autopsy that determined he’d suffered three blows to the head, and defensive wounds on his right forearm.

His mother, Lovely Varughese, has sued the man she believes killed him, the city of Carbondale, and Carbondale Police Chief Jody O’Guinn.

“Based on how my brother was treated in Carbondale and how my family was treated, they’re not doing their job,” said Varughese’s sister, Priya.

She said her family needs some sense of closure.

“Obviously the pain will never go away. But I think we do deserve some sort of peace,” she said.

Priya said the family just wants to know what happened.

“There are people out there that could give us those answers, and we just want to know the truth,” she said.

The city manager of Carbondale said he hasn’t seen the lawsuit, and declined comment.