Marsha: new CCTV pictures

New CCTV pictures that could provide a breakthrough in the search for the killer of gap-year student Marsha McDonnell have today been released by detectives probing her murder.

The images show eight passengers on the bus from which the 19-year-old disembarked shortly before being attacked with a hammer yards from her home.

Police released the images as detectives confirmed they were investigating the possibility that Marsha was the victim of a serial attacker who may have struck twice before.

A teenage girl who previously believed she had blacked out after slipping on ice and a middle-aged man attacked by a man with a hammer on New Year's Day are possible victims.

Marsha got on the 111 service at 12.07am last Tuesday at Kingston station after a night at the cinema with friends. She got off 10 minutes later at Percy Road just past the junction with Priory Road, Hampton. As she walked along Priory Road she was hit three times over the head, possibly with a hammer. She died in hospital on Wednesday night.

A spokesman said: "The pictures could help jog somebody's memory. It is vital that anyone with information comes forward."

Officers emphasised that none of the men on the bus were being treated as suspects but said they might have evidence which could prove crucial.