This white Ford Transit van has been linked to the shooting of two men in Tredworth this week.
Detectives investigating the case have issued a CCTV image of the van which has the registration number MV52 ZZN.
They want to hear from anyone who may have seen the van or may know where it is now.
Two brothers were shot through the front door of a house in Falkner Street shortly before 4.15am on Tuesday.
One of the victims, a 46-year-old man, remains in hospital with a serious arm injury while his 47-year-old sibling has been discharged after suffering less serious injuries.
Detective Chief Inspector David Sellwood said: "We believe this van is connected to the shooting and was nearby when it happened.
"It is a white Transit van with the registration number MV52 ZZN."
DI Sellwood said: "We firmly believe that this white Transit van was involved in the incident." He said he believed three or four men were involved in the shooting and that the van was near the scene at the time.
"The premises that were attacked were attacked by mistake and the victims have no criminal connections at all," he said.
"We know the address that should have been targeted and have been in touch with the occupants of that address. We've put measures in place to protect against any future risk.
"We know who the intended victim was and he does not reside at that address - he was an infrequent visitor. Measures have been put in place and he will not go back to that location."
DI Sellwood said the vehicle was "really important" to the investigation.
Anyone with information is urged to call 101, quoting incident 36 of April 2.
