A North Texas deputy sheriff and his son died in a murder-suicide, officials said.

Officers were called about 10:40 a.m. Thursday to the home of Joseph Parker in the 1300 block of Cherry Street after a family friend discovered two bodies in a bedroom, Graham police said.

Preliminary rulings from the Tarrant County medical examiner's office show that Parker shot his 27-year-old son Kensy, then himself, police said.

Parker, 61, was last seen Jan. 24 when he left work early at about 4:30 p.m. The last time he had contact with anyone outside the home was through text message at about 9 p.m., police said.

Graham police said in a prepared statement that the investigation has been difficult "for all the departments in our area."

Parker and his son each had a single gunshot wound, and there was no sign of a forced entry or struggle. No note was found.

"We will probably never know the reasoning as to why this happened, and while we do not condone his actions, we remember his service to the community and our hearts go out to the family," police said.

Parker, who retired after 20 years as a Graham police officer, was the Deputy Sheriff of Young County. He also served as a firefighter and arson investigator with the Graham Fire Department.

Graham is located about 120 miles northwest of Dallas.