Aldridge stabbing: James Brindley was "most precious son"
The parents of a man stabbed to death on his way home from an evening with friends have paid tribute to their "most precious son".
James Brindley, 26, died on High Street, Aldridge, West Midlands, despite attempts by four schoolboys who rushed over to him to give first aid.
Detectives have released CCTV of two men they want to trace over the stabbing at 23:45 BST on 23 June.
The men are seen in the area before and after Mr Brindley died, police said.
Speaking at a news conference, Beverley and Mark Brindley appealed for information to catch their son's killer.
"How they can sleep at night, how they can continue on a day to day basis is beyond me," Mrs Brindley said.
"So if there's anybody that has seen any change in anybody they're associated with, live with, or has this person suddenly gone on holiday, please come forward."
Mr and Mrs Brindley said their son's death had been "like a bolt out of the blue".
Mr Brindley, previously described by his parents as "a very straightforward and trusting person", was stabbed in the heart.
The two men are seen in the CCTV footage in the Whetstone Lane and Churn Hill Road area of the town, both before and after James was stabbed on Little Aston Road by The Croft.
It is thought the men had come from the direction of Bosty Lane and headed back that way.
Det Ch Insp Chris Mallett said: "This is a significant development in our investigation and I would urge anyone who recognises either of these men to contact us as a matter of urgency.
"James' family desperately need answers and we are continuing to keep them updated with our investigation, but we also need your help to bring James' killers to justice."