The mother of a teenage Good Samaritan who was murdered when he tried to break up a fight is devastated and wants someone held accountable for her son's death.

Jamie Kehoe, 18, died Saturday morning after being stabbed in the chest on a Surrey transit bus. The Integrated Homicide Investigation Team has taken over the investigation.

Witnesses have told police a black man was involved in the fight and later took off running.

Kehoe's mother Tammy says her grief is overwhelming and she has no idea how she's going to get through this.

"I know I have a lot of people that are behind me and will help in any way they can but it's not going to help," she told CTV from an interview in Chilliwack on Monday.

Police issued an appeal to the suspect Sunday to turn himself in. And rumours are swirling on social media sites as to the identity of the suspect.

"He needs to be caught," said Tammy Kehoe, before breaking into tears.

"I have other children that need me so much. I don't know what to do. I don't know how I'm going to be able to go back to work. I don't know how I'm going to be able to take them to their sports activities. I don't know how I'm going to do it."

Jamie Kehoe was a skateboarder and a regular at the North Delta Skate Park. His friends describe him as quiet and cool.

Tammy Kehoe says her son was the type of kid who would try to stop a fight.

"Jamie was protecting someone, stopping the fight from continuing. And this jerk comes and stabs him and takes his life? There are angry people out there, very angry people," she said.

Homicide detectives returned to the scene of the crime Monday, scouring the surrounding area for any evidence, and likely the murder weapon.

Police are looking for anyone who saw what happened but one of their key witnesses will be Kehoe's best friend, who was also stabbed and suffered cuts to the back of his neck.

The bus company has not revealed if the bus driver saw what happened.

With a report from CTV British Columbia's Lisa Rossington