Six teenagers are being questioned by detectives hunting the killer of Rhys Jones.
The six - which include two girls - are among 10 suspects arrested by Merseyside Police over the shooting of the 11-year-old last Wednesday night.
Rhys died in the arms of his mother Melanie, 41, after being ambushed by a teenage gunman on a BMX. The Everton FC fan was shot through the neck by a bullet that has not yet been recovered.
Officers have confirmed a potentially key witness - a woman pushing a pram at the murder scene five minutes before the shooting - has been traced and is helping police with the investigation.
But Croxteth Park resident Emma Ahmed, 33, said Rhys's murder would not have happened if police had made good a plan to site a mobile police station on the Fir Tree pub car park - where Rhys was killed.
Mrs Ahmed, a solicitor who sits on the committee of the Croxteth Country Park Residents' Association, said: "We were promised a mobile pod, a mobile police station, and it should have been here in April and would have been stationed on the car park where Rhys died but police said they didn't have the resources.
"There is no doubt in my mind he wouldn't have died if that had been there."
Meanwhile, Rhys' brother has made his first visit to the huge floral shrine where his brother was killed.
Owen, flanked by four friends, delivered a large bouquet and remained to pay his respects for several minutes.
The 17-year-old also delivered an Everton rug bearing the motto "The People's Club". Placing it on the ground, he paused to look over the hundreds of bunches of flowers that have arrived since the shooting.
