POLICE hope that a forensic clue will lead them to the person responsible for murdering lorry driver Micky Little on the M3 at Camberley.
They are contacting "specific men" who live locally, and inviting them to take DNA mouth swabs to see if there is a match.
Detective Chief Inspector Graham Hill, senior investigating officer, said: "We have obtained forensic evidence which is of value to this investigation.
"At this stage, for operational reasons, we are unable to confirm what that evidence is."
Mr Little, 53, was killed when a brick was thrown from the M3 footbridge running from Brackendale Road, Camberley.
The brick smashed through the windscreen of his 44-ton articulated lorry and struck him on the chest.
Mr Little, of Hornchurch, Essex, managed to steer his lorry on to the hard shoulder before he collapsed and died from a heart attack.
He was employed by the Ford Motor Company which has offered a £25,000 reward for information which leads to the conviction of the person responsible for his murder.
Police want to hear from anyone who may have used the footbridge during the period of the incident, which happened sometime between 11pm on March 20 and 2am on March 21.
Witnesses should contact the police incident room on 01483 571212 or Crimestoppers on 0800 555 111, where calls are anonymous.