The men absconded from the category D Sudbury open prison over the weekend.
Three inmates walked out on Saturday though staff only noticed they were missing when they carried out a roll call that evening. The fourth left on Sunday.
One of the men, a 33-year-old burglar, was recaptured by police in the West Midlands on Sunday.
But burglar Warren Bamford, robber Christopher Price and Brett Frewin, who killed a father of three in a bungled burglary, were still at large last night.
Despite being classified as fit to be held at an open prison, police have warned the public they should not approach the men.
Detectives say all the men have connections to the West Midlands and officers are investigating if they colluded over their escape.
Police are appealing for information about their whereabouts, but say people should not approach them.
Frewin was one of four teenagers jailed for killing award-winning DJ Tushar Makwana.
The 37-year-old Heart FM presenter suffered fatal head injuries when he tried to stop the quartet escaping in a stolen car after he disturbed three of them breaking into his home. Read More