A teenager has been arrested in connection with the fatal stabbing of a 15-year-old boy attacked yards from his home.
Police said a 16-year-old male was arrested at his home in Wolverhampton on Wednesday and was due to be questioned later.
Keelan Wilson was injured following reports of violent disorder involving a group of people in Langley Road in the city's Merry Hill area at about 11pm on May 29.
On Tuesday, police visited the area and made a fresh appeal to the public for information in a bid to trace those responsible for the killing.
Officers described the arrest - the first since the investigation began - as a "significant development".
Police have personally appealed to a caller who rang with important information overnight, asking them to ring back.
Detective Inspector Warren Hines, from the force's homicide unit, said: "This is a significant development in our investigation.
"We are working on a number of leads and I am grateful to everyone who has provided us with information.
"I am particularly keen to speak to someone who called us with significant information, last night.
"Please call me back personally - I assure you that you can remain anonymous, as your information could be vital."
He added: "The community in Merry Hill, as well as the wider city of Wolverhampton, has understandably been rocked by the murder of Keelan and we are determined to stamp out this type of violence in our cities."
Keelan's death was the second fatal knife attack in the West Midlands in recent weeks.
It followed the stabbing of 16-year-old Ozell Pemberton near a bus stop in Sutton Coldfield, Birmingham, on May 17.
There have been at least eight serious knife-related incidents, including the fatal attacks, since May 12.
On Tuesday evening, the force's firearms officers were called to a disturbance in the street and seized weaponry including a hunting knife and a machete.