A murder victim who was stabbed through the heart while walking home from a night out died in his parents' arms, detectives have said.
West Midlands Police said officers investigating the death of James Brindley in Aldridge, near Walsall, are appealing for the occupants of four cars, who passed the scene, to come forward.
Officers have yet to find a murder weapon after Mr Brindley was attacked in the High Street shortly before midnight.
Giving an update on the inquiry's progress, Detective Inspector Jim Munro confirmed that the 26-year-old died at the scene in his parents' arms after they had rushed to his side.
Mr Munro said: "We know that four vehicles were travelling along Little Aston Road towards Aldridge town centre at the time we believe James was stabbed and we are very keen to speak to the occupants of those cars, two light in colour and the other two darker, as they may have seen what happened and could lead us to the killer.
"James had been out with friends that evening and was talking to his girlfriend as he made his way home alone.
"The attack lasted just seconds and four 16-year-old lads just leaving their school prom were the first to assist James by calling emergency services and providing immediate first aid.
"They were also able to get in touch with James's parents."
Appealing for information from the community, the senior officer added: "James's family and friends are devastated by his loss and we need to bring his killer to justice.
"Someone will have knowledge of this attack and I would ask them to search their conscience and do the right thing. If you can't speak to police then please call Crimestoppers anonymously."
Information can be passed to officers by calling West Midlands Police on 101 or Crimestoppers on 0800 555 111.