Police investigating the murder of a BBC worker are to make an appeal on the Crimewatch programme.
Mr Brown was killed the day before his 28th birthday
Tom Brown, 27, was stabbed to death as he walked home in the early hours of 21 August in Southgate, north London.
The Met has offered £15,000 reward for information about the death of the library assistant, who was killed the day before his 28th birthday.
The Crimewatch appeal will be broadcast on BBC1 next Tuesday - exactly a month after his murder.
Police believe Mr Brown left his friend's house at about 0300 BST and walked along Southgate High Street before being attacked outside Chandos Court on The Green.
Police have ruled out robbery as a motive for the attack, as he still had his wallet and phone with him when his body was discovered.
Police have issued an e-fit of the suspect
Det Ch Insp Keith Garnish said: "We continue to appeal for anyone who may have been in the Chandos Court area between 0300 BST and 0415 BST and seen or heard anything suspicious to contact us.
"Southgate High Street is a busy road and we are certain that someone must have seen something on the evening Tom was attacked.
"We are also keen to trace anyone who may have contacted the emergency service to request help for Tom and anyone who visited the cab office, Crown Cars, along Southgate High Street."
The Met has issued an e-fit of suspect who is described as white, of slim build with a gaunt looking face, about 5 ft 10 in tall with light brown hair, short at the sides and longer at the front.
He was scruffy in appearance and was wearing either a grey or white-hooded tracksuit top.
Police are also appealing for two other people, a man and a woman, who were seen sitting on a wall at about 0400BST 10 yards from the from where Mr Brown was killed.