BANGOR, Maine — There are four unresolved homicides on the books in Bangor — Trevor Sprague, March 7, in 2006; 8-month-old Aisha Dickson in 1997; Peter J. Bassett in 1988 and Effie MacDonald in 1965.

The Sprague case is “still active,” the Dickson and Bassett cases are “open and ongoing,” and the investigation into the death of MacDonald, who was killed 43 years ago, is “dormant,” Lt. Tim Reid, who leads Bangor Police Department’s detective division, said Friday.

“The ultimate goal is to resolve them and have a successful prosecution,” he said.

Having only “four cases that stretch back nearly 50 years” unresolved, is a fairly good statistic, considering Bangor is Maine’s third-largest city, he said, adding, “Any that are unsolved are too many.”

• Trevor Sprague, 34, was a transient from Lubec whose body was found burning under the Harlow Street bridge March 7, 2006. Police are releasing few details about his death, but have deemed it a homicide.

• Aisha Mariah Dickson was beaten to death in a Bald Mountain Drive apartment on Jan. 6, 1995. An autopsy revealed that nearly every bone in her 11-pound body had been broken in her short life, save for her spine. Her mother, father and grandmother were in the apartment at the time of her death, but each hired a lawyer and refused to talk to police, leaving investigators little to work with.

• Peter J. Bassett, 39, was an off-duty Bangor mail carrier who was shot and killed outside of Judy’s Bar and Grill on State Street on Aug. 13, 1988. Police found his body, still clothed in his postal uniform and with a gunshot wound to the head, several hours after he got off work.

• Effie MacDonald was a 54-year-old chambermaid at the Bangor House when she was raped and strangled to death with her nylons on March 18, 1965. She was slain in a room on the third floor of the downtown hotel. It sent a wave of terror through the community, prompted by speculation that she was killed by the Boston Strangler, whose activity in Boston was just hitting a peak in 1965.

While not considered unsolved murders, three people died during an apartment fire in downtown Bangor during February 1981 that was intentionally set, Reid said.

“Those basically are considered manslaughter,” he said. “Murder has to be premeditated. These people died as a result of the arson.”

Neither the arson nor manslaughter case was solved, and both are no longer active because the six-year statute of limitations has expired, Reid said.

Firefighters saved many of the occupants as the fire swept through the five-story McCann Building at 146 Main St., situated in the Brountas Block, but Jesse Eddins, Patricia Oakes and Donald Morrell perished.

Detective Brent Beaulieu is handling the Sprague case, Detective Tim Cotton is in charge of the Bassett case, and a replacement is needed for the Dickson case because lead investigator Detective John Robinson recently changed jobs, Reid said.