Lockhart had been missing since May. Her husband Christopher Lockhart was named a person of interest after police say he wasn't cooperating with the investigation.
On Tuesday, Christopher was found dead at his home in the 10000 block of Poplar Bluff in Portage. Police confirmed during a Wednesday press conference that he hanged himself.
Authorities also said during the press conference that he left behind a message with a map showing where Theresa's body was.
He also admitted to killing her on May 18 after he "snapped" during an argument, police said.
It took deputies in Allegan County just a few hours to find Theresa's body in Valley Township and the Allegan Game Area.
"As to the note found at (Lockhart's home), not only did that contain a hand-drawn map that led us to ultimately find Theresa, but it also contained a written confession by Chris Lockhart," said Portage Public Safety Director Nicholas Armold.
Lockhart had been missing for 154 days, according to Armold. She was a Spanish teacher at Schoolcraft High School. The school district issued a statement Wednesday saying counselors will be available for students.
Here is the full statement from Schoolcraft Community Schools:
It is with tremendous sadness and a heavy heart that Schoolcraft Community Schools acknowledges the passing of Theresa Lockhart. We are all saddened by her death and send our deepest condolences to her family, friends, colleagues and students. Like so many others, all of us at Schoolcraft Community Schools have been holding out hope for a very different outcome since the news of her disappearance last May.
Mrs. Lockhart was a part of the Schoolcraft Schools Family from 2015 to 2017, serving primarily as our Spanish teacher.
Counselors will be available for students who wish to talk, or are seeking support, over the next days. Any Information regarding funeral arrangements will be provided when available.
(The-CNN-Wire & 2017 Cable News Network, Inc., a Time Warner Company. All rights reserved.)