Detectives investigating the murder of a Hells Angels biker shot dead on the M40 motorway in what they believe was a pre-planned hit said on Friday the inquiry was making good progress.
Mr Gerard Tobin, 35, who lived in south London, died after being shot in the back of the head as he drove home from an annual biker event in Warwickshire on Sunday afternoon.
Detectives believe Mr Tobin, a motorbike mechanic, had been deliberately targeted after being followed from the Bulldog Bash and suspect the killer had been in a dark green or blue Rover 620.
They said it was possible that Mr Tobin had been targeted by a rival gang.
"I'm fairly sure from the circumstances somebody was intending to target either Gerry as an individual or Gerry because he was a Hells Angel," Detective Superintendent Ken Lawrence told a news conference.
"It didn't seem just a random attack on just anybody -- it was clearly focused on Gerry."
He said a fingertip search of the M40, which had caused a large section of the motorway to be closed for about 24 hours, had been "very helpful" but would not elaborate.
"We've made some significant progress," Lawrence said. "In less than a week we've made some good progress."
He said people who knew Mr Tobin had spoken very highly of him, describing him as a hard-working man.