Police believe the pictures of Victor Farrant, 45, were taken in the kitchen of the home of Glenda Hoskins, also 45, a mother-of-three who was murdered by suffocation.
One shows Farrant happily helping out in the kitchen. The second shows him smiling into the camera as he stands against a drawn curtain in the house.
The photographs were taken just weeks after Farrant became Mrs Hoskins's boyfriend following his release from prison in November last year.
Detectives say there is an evidential link between Farrant and the attempted murder of Ann Fidler, 43, at her home at Eastleigh, Hampshire, last December. She was left for dead after being attacked with a knife and bottles.
The new photographs are said to be a more up-to-date likeness of Farrant, who is greyer and thinner in the face than a previously published photograph.
Detective Chief Inspector Paul Stickler, deputy senior investigator in the inquiry, said: "The new photos could be crucial to the inquiry. Witnesses have said this is a much better likeness than previous pictures."
Police have warned anyone who may be sheltering Farrant that he is "extremely dangerous" and should be surrendered. They believe there is a chance he may have fled abroad, and he is known to have connections in Belgium.
On the day of the murder of Mrs Hoskins at Port Solent, Hampshire, last Wednesday, Farrant was seen driving her car in Portsmouth and Brighton, and the vehicle was later found in Plaistow, east London.Reuse content