A man convicted of killing a California woman also murdered a woman and three girls in New Hampshire and may have had more victims, New Hampshire authorities said on Thursday as they unveiled new details about a decades-old cold case.

Officials in the state capital Concord named the suspect as Bob Evans and said he died in prison in 2010, seven years after he was found guilty of murdering his wife in California.

Evans is now believed also to have killed another woman and three girls aged 1 to 11 whose bodies were found in oil drums near a state park, and is suspected in the 1981 disappearance of his former girlfriend from Manchester, New Hampshire, the officials said.

"We believe we have our killer. Now we have to identify the other victims," Assistant New Hampshire Attorney General Jeffery Strelzin told a press conference.

"He certainly fits the profile of a serial killer," Strelzin added.

Two of the bodies found near the state park north of Manchester were discovered in 1985, and the other two in 2000. None of those four victims have been identified.

Evan's ex-girlfriend, Denise Beaudin, was 23 when she went missing. The house in Manchester where she lived was searched last week by agents from the Federal Bureau of Investigation.

Investigators said they got several breaks in the case in recent months, including DNA test results that showed one of the murdered girls was Evans' daughter. The other two girls were found to be daughters of the murdered woman, who is not Beaudin.

Officials said Evans left Manchester with Beaudin's infant daughter after his former girlfriend's disappearance, but later abandoned her in California. Beaudin's daughter is alive and well, they added, and cooperated with the investigation.

Strelzin said Evans exhibited a pattern of abuse toward women and children and that there may be more victims, given that there are many "blanks" in his life history.

Evans, who officials said used at least five aliases, is believed to have been in his 60s when he died. But authorities said they were not certain due to his multiple identities.