Theresa Joan Lockhart
Theresa Joan Lockhart, 44, whose husband confessed to her murder in his suicide note Kalamazoo County Silent Observer Program

Police in Michigan have said that a man has confessed to killing his wife and gave authorities a map to her body after taking his own life on Tuesday (24 October). 44-year-old Theresa Joan Lockhart had been missing since 18 May and was last seen around her home in Portage.

Portage Department of Public Safety said that Lockhart's husband, Christopher Lockhart, had been found dead during a welfare check. "The preliminary investigation indicates signs of a possible suicide," the department said in a statement.

According to local reports, authorities then said during a press conference that Lockhart had left a hand-drawn map which led police to Theresa's body in an wooded area 50 miles from the home the couple had shared. Along with the map, Lockhart had left a note confessing to his wife's murder, police said.

WXMI reported that Lockhart had been a person of interest in his wife's disappearance but that authorities had lacked evidence. Lockhart said in the note that he had "snapped" when the couple had had an argument, police told reporters.

Director of public safety, Nick Armold said that Lockhart had hanged himself and was found in the basement of his home, Michigan Live reported, adding that in the note, Lockhart had asked for forgiveness.

"When you know what you know but you can't prove it," Armold said in footage published by WXMI, "we kind of had an idea and we just didn't have enough to run with it." Lockhart was discovered after he failed to report himself at Kalamazoo Office of Community Corrections.

Lockhart may have died over a day before authorities discovered his body, police said. His wife's body was found partially uncovered from rain in a game area in Allegan County but deputies said it appeared to have previously been fully buried.