NEWPORT, N.H. – A New Hampshire fire investigator says he doesn’t believe a lit cigarette started the fire that killed a Keene family of four in an adjacent apartment in 1989.

Lawyers for 54-year-old David McLeod are in court challenging evidence prosecutors say shows that McLeod set the fire that killed a newlywed couple, their 4-month-old daughter and the man’s 12-year-old daughter.

Retired state fire investigator Thomas Norton says he initially thought a dropped cigarette may have started the blaze, but discounted that after talking to apartment resident Sandra Walker.

“I wondered why Sandra Walker was not seriously injured or dead,” Norton testified Tuesday in Newport Superior Court. “She was, by her own admission, intoxicated that night.”

Walker, who has since died, at first told police she thought she must have fallen asleep on the couch while smoking. But a few days after the Jan. 14, 1989 fire she told police she never slept on the couch and awakened to a fire burning on the foot of her mattress and ran to the bathroom for water to put it out. She told Norton she could see clearly, the room was not filled with smoke.

She told Norton when she returned to the room with water to douse the fire, flames were engulfing the apartment and she fled instead.

“I concluded this was not a slow-developing fire,” Norton said. He testified he believes the source of the fire was open flame, probably from a lighter or matches, igniting the couch. Norton testified he ruled out appliances and the electrical box as sources of the fire.

On cross-examination by defense attorney Caroline Smith, Norton acknowledged his conclusions were influenced by reports that McLeod had threatened to burn down the house where his ex-girlfriend was living. Witnesses quote McLeod as saying after the fire that he “torched the whorehouse.”

Killed in the fire were Carl and Lori Hina, their 4-month-old daughter, Lillian, and 12-year-old Sara Hina. Fifteen residents of the eight-unit apartment building survived.