The circumstances surrounding Sunday’s fatal shooting of two men in Biddeford remained a mystery late Wednesday after two ex-convicts sought for questioning voluntarily reported their whereabouts to police.

One of the ex-convicts, Christopher Dube, 28, of Dover, New Hampshire, was interviewed Tuesday evening. He is being held without bail at York County Jail while awaiting a court hearing on charges of violating his probation, police said.

The other man, Lance Palmer, 44, of Auburn, was to be interviewed Wednesday night, said Steve McCausland, spokesman for the Maine State Police.

Police did not say the men are suspects and have announced no charges in the deaths of Russell Lavoie, 42, of Old Orchard Beach, and Jeffrey Lude, 37, of Biddeford. They died of multiple gunshot wounds after a shooting about 7 p.m. Sunday in an apartment at 19 Western Ave. Neither of the men lived there.

Dube, who was sentenced in 2012 to 18 months in prison for burglary and forgery, was on two years of probation as a condition of his release Jan. 3, according to the Maine Department of Corrections. His probation officer moved in April to revoke probation, alleging that Dube tested positive in February for the active ingredient in suboxone, failed to report to his probation officer in New Hampshire on four occasions in March, left for Florida in April without permission and failed to report to his Maine probation officer in April.

State police said Dube and Palmer “may have been in Biddeford on Sunday” and “may have information on the shootings.” Both men have lengthy criminal records.

Palmer, of Auburn, served nine years of a 10-year sentence for burglary and aggravated assault related to a home invasion in the Bangor area. He was released April 21, 2012, according to the Department of Corrections. Palmer has 24 prior convictions, including 13 for assault, according to the State Bureau of Identification.

Dube, who has lived in Biddeford, has a dozen convictions, including stealing drugs, numerous thefts and assault, according to the bureau.

Police called Sunday to 19 Western Ave. found Lavoie and Lude mortally wounded. Lavoie died in an ambulance. Lude was taken first to Southern Maine Medical Center in Biddeford and then to Maine Medical Center in Portland, where he was pronounced dead, police said.

Although neither Lavoie nor Lude lived at the apartment building, the shootings were not random, police said. The two had a reason for being in the apartment, but investigators would not elaborate.

Police would not say whether a gun was recovered, or whether they found evidence of criminal activity in the apartment.

Police initially were looking for two men and two women who had been in the apartment and apparently ran after the shooting. Those four were located, police said.