A two-day manhunt for James Barton Horn Jr. ended Saturday with police killing the double homicide suspect.

Horn was being sought in the shooting deaths of Sandra Sutton, 46, and her 17-year-old son, Zachary Wade Sutton, who were found dead Thursday morning at a house in Clinton, Mo.

Officers acting on a tip found Horn late Saturday morning inside a house at the Kearn Memorial Wildlife Refuge near Green Ridge, Mo., said Clinton Assistant Police Chief Sonny Lynch.

The house, owned by the Missouri Conservation Department, was not occupied, according to Sgt. Bill Lowe of the Missouri Highway Patrol.

Police had been searching abandoned houses and other structures in the area. They arrived at the wildlife refuge house about 11:15 a.m. Saturday, Lowe said.

Officers found Horn hiding in a closet, armed with a handgun. When he displayed it in a threatening manner, officers fired.

“They felt that their lives were threatened,” Lowe said.

Investigators said they had not determined if Horn fired any shots before he was killed.

Horn, 47, was a former boyfriend of Sandra Sutton. He was charged earlier this month with holding her captive in a wooden box inside a home in Sedalia, Mo.

Police had been looking for Horn since April 30, when Sandra Sutton ran to a neighbor’s house in Sedalia and called police. She told them that Horn had confined her in the house for four months, at times holding her inside the locked wooden box.

A Pettis County arrest warrant was issued in early May after prosecutors charged Horn with kidnapping, armed criminal action and unlawful use of a weapon.

While police looked for Horn, Sandra Sutton moved in with relatives in Clinton.

On Thursday morning, her relatives came home from work to find her and her son, a junior at Clinton High School, dead from gunshot wounds.

Clinton police almost immediately named Horn as a suspect in the killings.

Horn had a history of kidnapping and assaulting women. He moved to Missouri in 2012 after being released from federal prison.

Federal authorities had sought to prevent his release by having him declared as “sexually dangerous.” But a federal judge in North Carolina denied the request.

Horn had been listed on the Missouri sex offender registry for the 1992 kidnapping and rape of a woman in Tennessee.

After his release from prison in that case, he was charged by federal prosecutors in Mississippi with interstate kidnapping.

Horn broke into the home of a woman he had formerly had a relationship with. He locked her 8-year-old daughter in a bathroom and raped the woman, according to federal court records.

He then forced the woman to withdraw money from an ATM, locking her in a car trunk and drove her to Springfield, Mo., where he continued to threaten and abuse her.

They then drove to Kansas City where FBI agents rescued her from a motel room where Horn had been holding a knife to her throat. He was subsequently sentenced to nearly 13 years in federal prison.