An 18-year-old man has been arrested on suspicion of murdering Leonne Weeks, 16, who was found dead on a path in Rotherham.
Police think a 19 year old knocked off his bike and killed in Luton was murdered as part of an ongoing family feud.
Delaney Brown, 19, (pictured) was hit by a stolen BMW while cycling along Vincent Road in Luton on the afternoon of Wednesday 5 September 2012.
The 19 year old died instantly from a broken neck in the high speed impact, which threw him from his bike.
Detectives have revealed that they believe the driver may have been waiting for him to appear.
Bedfordshire Police are calling on anyone who saw what happened to "do the right thing" and come forward.
Delaney had just got off the train with his bike and was cycling along Vincent Road at about 4.30pm when he was struck.
Police returned to the scene on Wednesday 12 September to set up a road block to talk to drivers using the road. They also spoke to pedestrians and carried out house-to-house enquiries.
Unemployed Delaney, who had three brothers and lived in Bank Close in the Hockwell Ring area of Luton, had been involved in crime in the past but detectives were quick to rule out his death being gang related.
They stressed that they believe he died as a result of his family being involved in a long running dispute with another family in the town.
Delaney was pronounced dead at the scene. He had sustained a broken neck and he also had crush injuries which could have occurred when his body hit a garden wall.
The following morning, the car - a silver one series BMW - was found in Morris Close on the Marsh Farm Estate in Luton.
It had damage to the front consistent with a collision.
Detective Chief Inspector Steve Collin, who is leading the murder hunt, said: "I believe this car was the vehicle which was used to kill Delaney.
"It is a stolen vehicle, originally from the Hounslow area, with the index number WF11 RWV and I am seeking any information relating to where this car has been since it was stolen on July 16 and information relating to those who abandoned it.
"Two people have been arrested in connection with Delaney's death.
"A man aged 26 has been released without charge and an 18 year old has been arrested of suspicion of murder and released on police bail pending further investigations."
DCI Collin from the Bedfordshire, Hertfordshire and Cambridgeshire Major Crime Unit revealed that people who have information regarding Delaney's death have not come forward.
He said: "There are people out there who can help solve this murder. Some of them may have already made up their minds in choosing not to help us. If that is the case, I am here today to try and change their minds.
"There are a lot of people who knew Delaney and the sort of person he was, or was perceived to be. These are the people I need to come forward and help this investigation.
"However, I can confirm that I have a suspect in mind but, for operation reasons, I cannot name this person at this time."
He added: "I firmly believe that the person responsible for Delaney's murder is local and will be known by this community. My appeal here today is to appeal to those people to come and talk to the police. I appeal to them today to put yourself in this family's position and do the right thing."
Police investigators know that Delaney spent the afternoon of Wednesday 12 September in Luton town centre.
He had his bike with him and later boarded a train with it from the centre of the town to Leagrave Railway Station. There he got off and began cycling along Vincent Road.
Police officers had been told that the stolen car which struck him may have been in the area for some time prior to the collision.
Along with the driver, it is thought there may have been others in the vehicle.
In the past, police said Delaney had been involved in robberies in the town and carrying weapons.
DCI Collin said enquiries so far revealed that the teenager may have been targeted and killed because of a dispute involving his family and another family in Luton.
The officer said at one stage both families had been on good terms, but there had been a dispute and a fall out.
He said he believed his suspect was a member of the other family who, at one stage, may even have been friends with Delaney.
Anyone with information about this incident are asked to call detectives on 01707 355666. Alternatively, you can call Crimestoppers anonymously on 0800 555 111.
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