It has been five weeks since anyone has seen or heard from Theresa Lockhart. The 44-year-old high school Spanish teacher from Michigan was reported missing on May 20 to authorities at the Portage Department of Public Safety.
For weeks, officials and community members have searched for Theresa, and police have announced they are treating the investigation as a “possible homicide.”
Here are five things to know about the case:
1. She Called in Sick to Work Before She Went Missing
Beginning on Monday, May 15, Theresa called in sick to Schoolcraft High School. She called in sick again on Tuesday and Wednesday, which appeared perfectly normal. But then she didn’t show up for work Thursday and Friday and didn’t call in sick. “That was not normal,” says Schoolcraft Community Schools’ Superintendent Rusty Stitt.
After the initial investigation, police officials said she was last seen leaving a local fitness center about 5 p.m. on Thursday, May 18, and she had communications between 8 and 10 p.m, though police did not say with whom.
2. Her Employer, and Not Her Husband, Reported Her Missing
On Saturday, May 20, after Theresa’s colleagues began to become concerned, they went to her home, which she shared with her husband Christopher.
He allegedly answered the door and said he would call the authorities if she didn’t show up by Monday. “That just didn’t jibe with me,” Stitt tells PEOPLE. “So I made the call on Saturday.”
3. Her Husband Has Been Named a Person of Interest
Police now believe Theresa might be dead, Portage police tell PEOPLE. Christopher, her husband — who did not return a message from PEOPLE seeking comment — has been named as a person of interest in the case.
“He hasn’t cooperated pretty much from the beginning — very little, if any,” Blue tells PEOPLE.
Christopher reportedly wouldn’t allow the police to search the home he shared with his wife, so on June 7, officials served him with a search warrant.
Authorities have searched far and wide for Theresa, including in a nearby body of water. They found her vehicle near a Park and Ride a few miles from her home.
4. Her Marriage Was Reportedly Strained
Theresa’s sister Joan Mullowney told The Huffington Post she contacted Christopher Lockhart when she heard the news about her sister’s disappearance.
“He wasn’t very forthcoming with information,” Mullowney said. “To be truthful, he seemed rather lackadaisical in his attitude … definitely not the attitude of a loving husband whose wife is missing.”
Mullowney said the couple met on an online dating website in 2006 and were married in 2007.
Jen Zimmerman, who went to college with Theresa and spoke with her the day before she went missing, told local news station WZZM that the couple had been working through some issues for the last few months.
“They were hitting a really rough patch,” Zimmerman said.
5. She was a Spanish Teacher Who Loved to Exercise
Theresa was very passionate about her work, Stitt says. She taught Spanish class in high school, and taught a leadership class at the middle school. She contributed to after-school committees, including as the advisor to the school’s National Honor Society.
“She was well liked,” Stitt says.
She also loved to exercise and would teach free wellness classes to her colleagues. “She was big into Zumba,” Stitt added.
As the search goes on, the community still clings to the hope of good news.
“There’s not a day that goes by that we don’t think about her,” Stitt says. “We’re still optimistic and hopeful here.”