A man who allegedly kept his ex-girlfriend captive for four months before she escaped is now the suspect in her death, local reports said.

James Horn allegedly shot Sandra Kay Sutton, 47, and her son, Zachary Sutton, 17, to death inside a Clinton, Mo. home. Their bodies were discovered early Thursday, just weeks after Sandra Sutton escaped a wooden box inside Horn's Sedalia home, according to WDAF-TV.

The 47-year-old suspect, a convicted sex offender, has been on the lam ever since Sutton escaped the makeshift prison the night of April 30. She had been staying with relatives in the Kansas City area without seeking police protections against Horn since her escape, authorities said.

Since the discovery of both bodies, police have surrounded Horn's home in Sedalia where they believe he may be hiding. That's where Horn allegedly kept Sutton inside the box, which investigators said contained a bucket, reading material, sleeping bag, flashlight.

Relatives came home from their overnight work shift shortly after 4 a.m. to find the mother dead in a bedroom and her son's body on a staircase, KSHB-TV reported.

Horn faces charges of kidnapping and now murder in the wake of both Sutton and her son’s death.

Horn was convicted of a sex crime in Memphis, Tenn, where in 1992 he assaulted a 22-year-old woman.