Crime Solvers Central
Crime Solvers Central
298 Cases Solved. Advancing justice for missing persons, unsolved homicides, unidentified and unclaimed remains.

Case Description

Any updates on this case? Let us know!
Summary based on the NamUs case record (MP43527) and 5 other sources
On a Monday in the fall of 2003, a 29-year-old mother named Theresa Marie Lamontagne finished her workday and went to her mother's house in Roseville, Michigan. It was September 29th, and Theresa, a resident of nearby New Haven, needed a ride home. Dressed in her medical scrubs and gym shoes, she began calling people to arrange transportation. The day was marked by a sense of unease, as Theresa expressed to her mother that she was feeling overwhelmed, stating, 'Everything's getting to me, Mama. I gotta get away.' While she was waiting for a family friend to pick her up, she vanished. In one version of events, the friend called to say they were on the way, but Theresa was nowhere to be found when they arrived.

Another account of her last known moments came from her brother, who was in another room at their mother's house. He reported hearing the front door slam and hurried to a window just in time to see his sister get into the passenger side of a white sedan. The car, which was unfamiliar to the family, had an unknown individual at the wheel and drove away, carrying Theresa into a mystery that has now spanned decades. Her family has not seen or heard from her since that moment. At the time of her disappearance, Theresa was described as a tall woman with sandy hair, green eyes, a scar above one of her eyes, and a tattoo on her thigh.

In the weeks and months that followed, Theresa’s family was left grappling with her sudden absence. Her twin sister, Julie Morosky, was haunted by questions and disturbing dreams about her sister's fate. The family acknowledged that Theresa had been under significant stress from her job, financial pressures, and a volatile relationship with her boyfriend, who had a past domestic assault charge. While Theresa had a history of leaving for short periods when feeling overwhelmed, her loved ones insisted this time was different. They stated she had never been out of contact for more than a week and would never have abandoned her three children, for whom she cared deeply. Law enforcement at the time, however, considered the possibility that she had left voluntarily. They received a tip that she may have run off with another man she was seeing. Despite this, the case remained an active missing person investigation as police acknowledged they had exhausted nearly all leads.

The investigation into Theresa Lamontagne's disappearance has left more questions than answers. The conflicting accounts of her last moments—whether she was waiting for a ride that arrived too late or if she left in a mysterious white car—complicate the narrative. Her family remains convinced that she would not have willingly cut off all contact, pointing to her strong maternal bonds as evidence that something tragic must have occurred. Law enforcement's initial theory that she may not have wanted to be found has, over the years, transitioned into a long-standing cold case. Without any definitive evidence of her whereabouts or what happened after she left her mother's home, the case of Theresa Lamontagne remains an unresolved and sorrowful mystery for her children, her twin sister, and the rest of her family who are still awaiting answers.

Last Seen: Sep 29, 2003

Possible Unidentified Matches (4)

Unidentified remains cases whose details are consistent with this person, ranked by how closely they compare. Fields that are unknown in either case are left out of the score.

82%Moderate
Jane Doe — Clay Township, Michigan
UP11547 • Found Oct 7, 2003
View case
Sex ✓Female
Age 85%Est. 30–50 vs 29
Race 100%White
Location 98%19 mi away, same state
TimingFound 8 days after last seen
Height 100%5'8" vs 5'9"–5'11"
Weight 93%175 lb vs 145–155 lb
76%Possible
Jane Doe — Highland Park, Michigan
UP8177 • Found Mar 30, 2009
View case
Sex ✓Female
Age 96%Est. 35–50 vs 29 when missing
Race 100%White
Location 100%10 mi away, same state
TimingFound 6 years after last seen
75%Possible
Jane Doe — Detroit, Michigan
UP11701 • Found Sep 30, 2008
View case
Sex ✓Female
Age 92%Est. 35–50 vs 29 when missing
Location 99%13 mi away, same state
TimingFound 5 years after last seen
Height 100%5'8" vs 5'9"–5'11"
Weight 84%118 lb vs 145–155 lb
75%Possible
Jane Doe — Detroit, Michigan
UP150506 • Found Sep 17, 2025
View case
Sex ✓Female
Age 100%Est. 38–52 vs 29 when missing
Race 100%White
Location 99%13 mi away, same state
TimingFound 22 years after last seen
Height 52%5'5" vs 5'9"–5'11"
Weight 100%147 lb vs 145–155 lb

These comparisons are generated automatically from public NamUs case data and are not confirmed identifications. Only DNA, dental or fingerprint comparison by investigators can confirm an identity. If you believe two cases are connected, contact the agency handling the unidentified case.