Police investigating the fatal shooting of two teenagers in Milton Keynes are going through hundreds of hours of CCTV footage in the hope of finding clues.
Amin Ahmed Ismail, 18, died in hospital after the shooting in an alleyway in Fishermead last Thursday night.
The other victim, Mohamed Abdi Farah, 19, of Birmingham, died from a single gunshot wound to the head.
Two men, aged 21 and 33, and a boy, 13, have now all been bailed pending further inquiries.
Police said three males from Bletchley had been arrested on Friday.
Both victims were from the Somali community and were known to police over low-level criminal activity.
Detectives have ruled out the killings being gang-related.
Det Supt Rob Mason said: "We have a large team of officers dedicated to this investigation and they are busy conducting house-to-house enquiries, speaking to witnesses and viewing hours of CCTV footage.
"I am convinced that we will find whoever was responsible for the deaths of these two young men."
The victims are known to have visited the Xscape leisure complex in Milton Keynes and left at approximately 2141 BST.
They then walked back to the estate and were last sighted in the vicinity of the X-Trim barbers shop in Gurnards Avenue at about 2150 BST.
Mr Mason said: "We would be keen to hear from anyone who saw our victims in the last few hours leading up to their deaths and particularly as they walked back from the Xscape building.
"The response from the public and the local Fishermead community has been excellent and I would like to thank anyone who has contacted us with information."