Family members of missing 911 operator Theresa Parker say they believe her husband may have something to do with her disappearance.

Parker's brother-in-law, Jonathan Wilson, told FOX News he had a feeling from the beginning — when Theresa went missing 12 days ago — that Samuel Parker may have had a hand in her disappearance.

The couple was in the midst of getting a divorce when Theresa disappeared 12 days ago.

Wilson said the Georgia Bureau of Investigation — which is heading up the investigation into Theresa's disappearance — took a DNA sample from Theresa's mother, Claire, who lives in LaFayette. Wilson said the sample was taken shortly after the Friday prayer vigil for Theresa, held downtown on the Walker County courthouse steps. Wilson believes the sample may be needed to help rule out DNA samples from evidence investigators have collected. So far, Wilson said, he doesn't know of any other DNA taken in the case.

Wilson said now that the GBI has named Sam a "person of interest," the family has the"green light" to go ahead and voice their concern about him.

Based upon conversations and actions from investigators, Jonathan also thinks the GBI is treating its investigation as foul play and narrowing down their focus to Sam.

The GBI obtained a search warrant for Sam Parker's home over the weekend. The LaFayette house had been searched two times before under consent; Parker was present during both searches. GBI obtained the search warrant based on leads in the investigation gained over the weekend. The warrant was executed around 5 p.m. Saturday.

Wilson said GBI was using the term "person of interest" for Sam Parker because the search warrant was executed on his home and thus, is one of their areas of concentration. A GBI spokesman told FOX News on Friday, however, that the agency never uses the term "person of interest" or names "suspects" until an arrest warrant has been issued.

"Sam has cooperated with the GBI each time the GBI has asked him to come in for the missing persons," Walker County Sheriff Steve Wilson told FOX News on Monday.

Asked if authorities were close to arresting someone in connection with Theresa's disappearance: "We are proceeding very cautiously with the investigation. We want to be sure we do everything that is right. I certainly don't want to put a timetable out there."

He added: "I don't foresee an arrest will be coming today, or tomorrow … we're going to go as the evidence leads us."

Christina Hill, Theresa Parker's sister, also told FOX News she had similar concerns about Sam Parker.

"I can honestly say that I do believe he's involved. That’s what I feel, that’s what I know in my heart," Hill said. “I know of an incident last year where she was really scared, she was really afraid. And she looked me in the eyes and told me that she was afraid that she was going to die."

Police say they have not classified Parker, a sergeant with the LaFayette, Ga., police department, as a suspect. His patrol car was routinely turned over to the Walker County Sheriff's Department, then to the Georgia Bureau of Investigations, to be examined. It was later returned back to the LaFayette police.

Theresa's other sister, Hilda Wilson, told FOX News she hasn't heard a word from her sister's husband since the search began, but refused to comment on whether she suspected him.

"We're still hopeful that we're going to be able to being her home safe and sound. If not we just want to bring her home," Wilson said.

Investigators continued a widespread search for Theresa Saturday that included more than 200 volunteers, a dive team and five dog teams.

There is no evidence pointing to another man in Parker's life, Wilson said, and there has been no use of her credit or debit cards since she disappeared. Her husband indicated her purse and an overnight bag were missing from the house she was living in, but besides that, the residence was immaculate.

Records show at least three domestic violence reports between Parker and her husband since 2002, according to local news reports. In one report, Theresa said she called police when she thought her husband was going to commit suicide while they were on vacation in Florida.

Sam Parker had moved out of the home he and his wife once shared, and Theresa was in the midst of moving to a neighboring town when she disappeared.

Relatives of Theresa Parker's contacted the Walker County sheriff's office on Saturday after she hadn't been heard from since around 10 p.m. March 21, when she got off the phone with her sister. It was Parker's habit to talk to her mother or other relatives at least once a day.

FOX News' Joe Hirsch contributed to this report.