Maine State Police are investigating a homicide in Amity in which three people were killed, and are looking for a pickup truck taken from one of the victims.

According to a news release from Maine Department of Public Safety spokesman Steve McCausland, the deaths were discovered by a relative of one of the victims around 9:30 p.m. Wednesday, June 23, at a home along Route 1 in Amity, about 15 miles south of Houlton.

The victims, which detectives said had been stabbed to death, are Jeffrey Ryan, 55, his 10-year-old son, Jesse Ryan, and 30-year-old Jason Dehahn, McCausland said in the release. The homicides took place at the Ryans’ house and detectives think the killings took place in the early morning hours of Wednesday. Dehahn was a friend of Ryan’s and also lived in Amity, McCausland said.

A team of Maine State Police detectives and representatives from the State Medical Examiner’s Office were at the scene throughout Wednesday night and the bodies were to be transported to the Medical Examiner’s Office in Augusta for autopsy Thursday, June 24, McCausland said.

Also Thursday, a team of state police detectives and crime lab personnel spent the day gathering evidence from Ryan’s property and conducting interviews.

Police are looking for Ryan’s 1989 Ford F-150 pickup truck, which was missing from the homicide scene, and are asking for the public’s help in locating the vehicle. It is blue and silver with Maine license plate number 4155RY; has two different-colored wheels — white wheels in front and silver wheels in the back; and running lights on top of the cab, above the windshield, according to the news release.

Police have received some calls from the public of possible locations of the truck, but there have been no confirmed sightings. Information on the truck has been entered into the National Crime Information Center in Washington, D.C., as well as with the Royal Canadian Mounted Police. The U.S.-Canadian border crossings in Aroostook and Washington counties also have been notified, as well as every police department in Maine, the release stated.

Photos of a similar truck also have been posted on the State of Maine and Maine State Police Web sites. Anyone who may have seen the truck since Wednesday should call Maine State Police in Houlton at 532-5400, or 911 on a cell phone.