Police say they are "determined to bring justice" for an eight-year-old boy and his mother who were shot on their doorstep a year ago.
Christian Hickey, then aged seven, was shot in the leg and Jayne Hickey, 30, was shot twice in her legs in the attack at their home in Salford, Greater Manchester.
Two men knocked at the door and one of them fired a number of shots after a brief conversation in which they reportedly asked for the boy's father, Christian Hickey senior.
Both mother and son are continuing to recovering from their injuries after numerous operations, say police.
Detectives investigating the shooting believe it is part of an ongoing feud between organised crime groups in Salford which has seen them arrest 18 people so far.
In July 2015 the city's "Mr Big", Paul Massey, was shot dead outside his home, although no arrests have been made over his murder.
Police are keen to speak to a motorcyclist and the occupants of car who were both passed by the offenders' vehicle as they sped off after the shooting in Gillingham Road, Eccles, on Monday October 12 last year.
A black Audi S3 was seen at 8.35pm in Dover Street, Eccles, and left a few minutes later before it returned to the same street just prior to the shooting at 9.25pm. Shortly afterwards, the suspects made off and travelled at speed along Worsley Road.
The first offender is described as white, between 19 and 20 years old, of 'chunky' build and wearing a baseball cap. He spoke slowly and with a Salford accent.
The second man is described as white and was also wearing a baseball cap.
Detective Chief Inspector Howard Millington, of Greater Manchester Police's Major Investigation Team, said: "It has been a year since a young boy and his mum were shot on the doorstep of their own home - somewhere they should feel safe.
"Christian and Jayne are recovering well but what happened to them will affect them for the rest of their lives and we are determined to bring them justice.
"It is believed the Audi drove at high speed close to a motorcyclist on Worsley Road causing him to pull over.
"The motorbike was a small motocross, possibly a 125cc, being ridden by a what looked like a young person. The bike pulled over and turned down a side street, possibly Hartington Road. A few seconds later the bike pulled out on to Worsley Road and drove off towards the motorway and out of sight.
"If this was you on the motorbike, or you remember seeing a black Audi S3 parked up on Dover Street or travelling at speed on Worsley Road, please get in touch with police.
"We are also trying to trace the occupants of a small dark-coloured hatchback saloon that had a broad stripe running diagonally from the front door over the wheel arches.
"The Audi was seen to pass this vehicle at speed on Worsley Road after the shooting.
"Salford is a strong and close-knit community and, if you do know something that may help our investigation, please get in touch.
"I want to stress that if you come forward with what you know you will have our full support. Or if you don't feel you can talk to police but you have information, you can speak to Crimestoppers anonymously."
Councillor David Lancaster, lead member for environment and community safety at Salford City Council backed the appeal for information.
He said: "This was an appalling crime and I urge anyone who knows anything at all to do the right thing and pass on that information. You can do so anonymously but please do act. Don't let the people who did this get away with it for a moment longer."
Anyone with information should call police on 0161 856 3400 or the independent charity Crimestoppers anonymously on 0800 555 111.