The 11-year-old was shot as he walked home from football practice
The chief constable of Merseyside has said police know who killed schoolboy Rhys Jones - and it is only a matter of time before he is caught.
The 11-year-old was shot dead as he walked home from football practice in Croxteth, Liverpool, on 22 August.
Despite 18 arrests in connection with the shooting, no-one has been charged.
But Bernard Hogan-Howe said on Radio Merseyside: "If the person is listening , we are confident we know who you are and are building a case against you."
He added detectives were "confident" the killer would be caught.
The chief constable said the case was progressing but that they could not publicise every success of the investigation.
He said: "What we can't do is shout about all the success we have, all the times we take a statement and all the times that people tell us another bit of the story.
"There has been wide reporting that people haven't come forward, but people have come forward and spoken to us."
Mr Hogan-Howe added: "I do understand an event like this knocks people's confidence in the justice system and yes there may be times when people worry it's not working but on the whole it does work and it will work in this case.
"So people have to judge us on the circumstances that develop over the next few weeks and months.
"We will get the person who committed this crime."
Police are still trying to trace a woman in a red car and a boy on a silver bike they believe could be key witnesses.
Detectives believe the woman nearly hit a youth, thought to be the gunman, as he cycled in front of her car.
A boy in his early teens was also seen cycling round the car park on a silver BMX just before the shooting at 1915 BST on the night of the murder.
Two BBC Crimewatch appeals, including a reconstruction of the shooting, have been made in an effort to identify the pair.
Leaflets have been dropped at houses in the area and police have sent messages to mobile phones and set up a large billboard on a main road near the crime scene in a bid to trace witnesses.