The murder of teenage model Sally Anne Bowman will be featured on the BBC's Crimewatch programme on Wednesday.
Model Sally Anne Bowman was killed just yards from her home
Miss Bowman, 18, was sexually assaulted and stabbed to death just yards from her south London home on 25 September.
Det Ch Insp Stuart Cundy who is leading the inquiry will be interviewed on the programme on BBC One at 2100 BST.
Police said on Tuesday that DNA tests may be carried out on men aged 20 to 40. It is thought the killer most likely lives or works locally.
DCI Cundy believes the man they are looking for is a serial sex attacker who may have committed around six other assaults.
Miss Bowman's murder in Blenheim Crescent, South Croydon, has been forensically linked to a sex attack in nearby Purley in 2001.
It is thought the same man attacked and robbed another woman just hours before killing the model.
DCI Cundy has described the killer as a very dangerous man who must be taken off the streets to protect women.
Miss Bowman's possessions, a white handbag, mobile phone, cardigan and purse are still missing - as is the murder weapon, thought to be a 12cm to 14cm knife.
The attacker is described as white, in his 20s or 30s, between 5ft 9in and 6ft and of medium build with short brown hair.