The body of a missing MI teacher was discovered Tuesday, the same day her husband was found dead in their home.
Lockhart confessed in the note to having murdered her on May 18 and disposing of her body on May 19 in an area approximately 50 miles away from their home.
After more than 100 days of searching, police recovered the body of Theresa Lockhart, a 44-year-old high school Spanish teacher from Portage, Michigan, who was reported missing in May.
His wife, Theresa Lockhart, had been missing since May, and he had been named a person of interest after police say he wasn't cooperating with the investigation.
He was found dead in the basement at their home Tuesday from an apparent suicide by strangulation. Police confirmed during a Wednesday press conference that he hanged himself. "We had an idea, but we didn't have enough to run with it", said Public Safety Director Nicholas Arnold.
Authorities visited Lockhart's house on Tuesday after he failed to report to the County Sheriff's office due to a DUI charge in July, concerned that Lockhart showed no movement for several hours (he had been wearing an electronic tag).
The note said he had killed Theresa on May 18 after he "snapped" during an argument, police say. After she vanished, cellphone activity and cellphone usage ceased, and none of her family heard from her. Theresa's husband, Christopher Lockhart, lawyered up immediately and refused to cooperate with police.
"In a shallow grave, we located the body of what has now been positively identified as the body of Theresa Joan Lockhart", Armold said. Her body was finally discovered this week-but it wasn't the first one officers came across.
Theresa Lockhart's college friend spoke to her on the day she went missing and said that the couple was working through some issues.
"That was not normal", Schoolcraft Community Schools' Superintendent Rusty Stitt told PEOPLE in June.