Police arrested a 16-year-old boy on Friday in connection with the shooting of a child whose death has shocked a nation and forced police to re-examine the country's already tough gun laws.
Rhys Jones, 11, who had been kicking a soccer ball around with friends on Wednesday night, died after being shot in the back of the neck.
Merseyside Police said they believed the weapon used was a handgun fired by a teen on a BMX bicycle.
The 16-year-old was arrested on suspicion of murder, Assistant Chief Constable Patricia Gallan said.
The arrest is the third in the case. Two other youths, aged 14 and 18, were detained by police on Thursday but released on bail within hours.
Such shootings are rare in Britain, where the gun homicide rate is a fraction of that of the US. Pictures of the boy and of his mother, Melanie, featured on the front pages of most national newspapers on Friday.
The Sun newspaper offered a ?100,000 (US$200,000) reward in yesterday's edition for information leading to the conviction of the child's killer.
Jones' heroes, the Everton soccer team, were to wear black armbands during their home game yesterday and join an expected crowd of 40,000 fans in a moment of silence to honor him.
Police will use the stadium's public address system to appeal for help finding the killer.
"We all here at the club have families of our own and we cannot comprehend what you are going through," Everton captain Phil Neville said in a message to Jones' family. "We appeal to anyone with information to contact the police."
The case has come after a steady drumbeat of heavily publicized youth killings throughout the country. In London alone this year, 18 young people have been slain -- 11 of them stabbed and seven shot.
Britain's Association of Chief Police Officers said it would review its gun control policies to see what it could do about taking illegal guns off the streets, although it noted that gun crime in the country was low.
Britain outlawed the possession of handguns in 1997 in response to the massacre of 16 children.