Updated

Detectives are trying to piece together why a Kentucky man fatally shot his parents and two other people before taking his own life last weekend.

Kentucky State Police said 45-year-old Joseph Nickell shot his parents at their home Saturday afternoon, then drove to his girlfriend's house and killed her and her mother before taking his own life in Johnson County, an Appalachian county in eastern Kentucky.

State Police Trooper William Petry said investigators on Monday were interviewing family members and neighbors.

"At this point, I don't see an indication of any problems he had with the family, of course we're still early in it," said Petry, a spokesman for the Pikeville state police post.

Petry said Nickell had some misdemeanor drug charges in his past, but investigators have not determined a motive for the slayings. A note written by Nickell was found at one of the crime scenes, he added, but police are not releasing its contents.

The family's pastor said Joseph Nickell had long struggled with drug problems and he saw the family in church earlier this month. Pastor James Kelly Caudill told The Lexington Herald-Leader that Nickell blurted out something during a service at Tom's Branch Free Will Baptist Church, but his mother calmed him.

Caudill said Joseph Nickell seemed to suffer a setback after the death of his sister.

Police said Nickell shot his parents, James and Arlene Nickell, both in their 70s, before driving to an apartment in Paintsville and shooting 41-year-old Lindsey Vanhoose and her mother, Patricia Vanhoose, 57. He used the same handgun in all the shootings, Petry said.

Nickell's teenage son was at the house where the first shootings happened but fled and called 911, police said.