OFFICERS investigating the murder of teenager Sheriff Mbye in Northfield are still trying to locate witnesses who were in a blue Fiat Punto at the time of the stabbing.
The car had a large sticker or item in the right corner of the back window.
The 19-year-old died in hospital after being stabbed on the Bristol Road South on Friday afternoon (April 17).
Another 19-year-old who also suffered stab wounds remains in a critical but stable condition in hospital.
Det Insp Jim Munro, from West Midlands Police CID in Birmingham, is leading the inquiry.
He said: “They (the people in the Punto) will have seen some or all of the incident as it happened and are likely to have vital information about those involved.
“We urge them to come forward as soon as possible and they can speak to us in confidence.
“The information they provide could prove crucial to our enquiries.”
He said the investigation was moving swiftly and the force had received a lot of support and information from the public.
But he urged anyone who witnessed the attack and had not yet come forward to speak to officers.
“Our thoughts remain with his family as they continue to come to terms with his death.”
Witnesses should call Force CID in Harborne by dialling 101 or speak to Crimestoppers anonymously on 0800 555 111.