A DC man has been charged with setting a fire that killed three people, including an ex-girlfriend, Sunday morning after a night of harassment — including other fires — in which police never took him into custody or even questioned him.

Jessica Cunningham, 34, and Ronald McKinnon, 64, were found dead after the fire was extinguished, WTOP reported. The third person, 85-year-old Margaret McKinnon, was still alive when she was found but died Monday at a hospital.

Robert Simpson, 56, has been charged with three counts of murder and arson.

Cunningham and the McKinnons called police several times Saturday night and reported actions by Simpson. Ronald McKinnon first called at about 7 p.m. when he heard windows breaking. He came downstairs and saw Simpson according to court documents. When police arrived, Simpson was across the street in Maryland, so officers did nothing but take a report.

Two hours later, McKinnon called again and reported flames at the back of his home. He told officers he again found Simpson, this time behind his house, and the suspect told him he would “mess up this house.”

Firefighters determined that the fire had been set in a trash can and on a shade in the window. The fire was intentionally set, investigators said, but police left again without finding Simpson.

At about 3:30 a.m., Cunningham called 911 and reported that Simpson had assaulted her Saturday morning. She said that Simpson had frequently attacked her and wouldn’t stay away, court documents said. She said she remained at the house and wouldn’t go to the hospital after the attack because she was afraid Simpson was lying in wait outside.

This time, police looked for Simpson for about an hour, even though the call was not about an immediate sighting of him.

Reports of the fatal housefire came in at about 5:30 a.m., or about 30 minutes after police stopped looking for Simpson. Several 911 calls reported the fire, including one believed to have come from Cunningham.

“He came back,” she said. “The house is one fire.”

Charging documents say the fire, which appeared to have been set in the living room, was set in places that made it impossible for the occupants to escape.

Surveillance footage from a neighbor showed a suspect come to the house, and then a “large flash of light” preceded the flames. Firefighters were on the scene in minutes and put out the fire, but it was too late. They returned to the neighborhood on Monday to talk to neighbors about fire safety.

Police finally arrested Simpson within an hour of the fatal fire. D.C. police Chief Pamela Smith defended the department’s lack of action throughout the previous night.

“We had officers in the area,” she said. “We just had to continue to answer radio calls.”

“We just wouldn’t just sit officers at a particular location for an extended period of time,” she added.

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[Featured image: WTTG screenshot]