A 16-year-old boy has been arrested in connection with the fatal shooting of 11-year-old Rhys Jones in Liverpool.
Rhys had been playing football with friends when he was shot by a youth on a black BMX bike at a pub car park in Croxteth on Wednesday night.
Police said the arrested boy was held on Broadway in nearby Norris Green.
An abandoned bicycle has been found in an area with a different postcode to the shooting, and it is being examined, said police.
Officers also confirmed descriptions of the killer's firearm, describing it as a black handgun with a long barrel.
Earlier police urged local people to come forward to help identify the killer, and said they were disappointed with the response from the public.
Assistant Chief Constable Patricia Gallan said someone in the community knew who had shot Rhys.
"We need to get this killer off the street. Within this community people know who is responsible for this crime," she said.
"We need your help. Come forward now and help put the suffering of Rhys's mum and dad at an end."
Merseyside Police said they would protect any witnesses who came forward and would guarantee their anonymity.
Rhys was shot in the car park of the Fir Tree pub at about 1930 BST. His mother Melanie held him as paramedics battled for 90 minutes to save his life.
Two local boys, aged 14 and 18, who were arrested on suspicion of murder, were released on Thursday night.
Merseyside Police have been handing out leaflets in the area with a special number for young people to text information anonymously.
Anyone with information can text the word "crime" followed by their message to 61051.
Speaking at a news conference on Thursday, Rhys's mother made a plea for her son's killer to be found.
She said: "Our son was only 11, our baby.
"This should not happen, this should not be going on. Please help us."
Rhys's father Stephen said: "We have lost our world, the world has lost a good guy."
Rhys supported Everton, and the club is to hold a minute's silence in his memory before Saturday's home game against Blackburn Rovers.
Players from both teams will wear black armbands.
The club has sent a message of condolence to Rhys's family, while captain Phil Neville has joined calls for members of the community to come forward with information.
''On behalf of everyone here at Everton Football Club and the players especially, I send my condolences to the Jones family on the tragic death of their son Rhys," he said.
"We all here at Everton have families of our own and we cannot comprehend what you are going through."
Relatives, friends and neighbours gathered at a vigil for Rhys at Emmaus Church of England and Catholic Primary School in Croxteth on Thursday evening.
It is near the place where Rhys was shot on his way home from football training.
Tony Edge, who broke the news of the shooting to the family has also appealed for people to come forward.
He said: "Tell the police, they don't have to give their names or anything, they just have to give this person up.
"This is a little kid who went to play football, who doesn't do any harm to anyone.
"I had an image of Rhys, this little laughing boy, and my final image of him isn't that, my final image of him is him lying there in a pool of blood."