Bullets could lead to Tas cold-case killer

Police believe the killer of a Tasmanian man watched his victim's movements before lying in wait to shoot him.

The body of Shane Geoffrey Barker, 36, was found in the hallway of his Campbell Town home after he was shot while attempting to lock his garage in 2009.

Tasmanian police have now returned to the crime scene where they are searching for bullet casings and more information about where the killer was hiding.

At least 18 people have come forward with information related to the cold case since Tasmanian police posted a record $250,000 reward appealing for more information.

Police believe they have already spoken to the killer.

Detective Sergeant Mark Lopes said on Tuesday investigations are likely to last for the next few months as they close in on the killer.