FARMINGDALE (AP) – An Augusta man found Wednesday in his pickup truck with a self-inflicted stab wound was under investigation following the abduction and murder of his 74-year-old mother-in-law, police said.

The death of Janet Hagerthy was ruled a homicide by Maine’s chief medical examiner, Dr. Margaret Greenwald, who listed “multiple traumatic injuries” as the cause of death, said Stephen McCausland, spokesman for the state Public Safety Department.

Police believe that Hagerthy was abducted between 5 p.m. and 6 p.m. Tuesday from her home on Easy Street by her son-in-law, 54-year-old David Grant of Augusta. Her body was found at about 8:30 a.m. Wednesday by a passer-by on Kennebec Street, McCausland said.

Authorities were alerted to the abduction by Hagerthy’s daughter after she arrived at the home and discovered her mother missing and signs of a struggle.

Grant, a self-employed carpenter, was found early Wednesday by Somerset County sheriff’s deputies inside his pickup truck along Route 2 in Palmyra, about 50 miles from Farmingdale, McCausland said.

Grant had a self-inflicted stab wound and was taken to Eastern Maine Medical Center in Bangor, where he is expected to survive following emergency surgery, McCausland said.

Police didn’t have any theories on what precipitated the attack, and no charges have been filed, McCausland said.

“At this point we’re still trying to determine the circumstances under which this abduction took place,” he said.

McCausland said a knife was found in Grant’s pickup truck, but he declined to talk about any other evidence that has been gathered.

Hagerthy was a widow who had lived in the same house for decades and was a retired nurse from the Togus VA Medical Center in Augusta, said Robert Mathews, a neighbor on Easy Street.

Mathews said Hagerthy’s daughter, Cindy, called his wife at about 8 p.m. Tuesday asking if she had seen her mother. He said the daughter by that time had already alerted police about her mother’s disappearance.