A Wisconsin mother who has been missing for two weeks may have been helping authorities in a criminal case against her ex-boyfriend, WKOW-TV reports.

Melissa Trumpy, 37, went missing in late October in Green County, Wisconsin, which is located south of Madison and runs along the state border with Illinois.

Investigators believe that the woman was last seen in the city of Monroe with her former boyfriend, Derek Hammer, shortly before she vanished.

Trumpy is said to have departed her job providing care for a disabled person around 10:30 p.m. on Oct. 26, according to the Journal-Standard.

She is then believed to have visited Hammer at his home in Shannon, Illinois, where he lives with his mother, the newspaper reports.

“He had been calling her asking her to come there and hang out,” Mandy Mboge, Trumpy’s sister, told the Journal-Standard.

Two days later, on Oct. 28, law enforcement issued alerts that Trumpy had vanished. That same day, police also arrested Hammer for bail jumping, alleging that he improperly had contact with Trumpy in violation of bail conditions.

Both Trumpy and Hammer had been charged in October with a felony count of maintaining a drug trafficking place, court records show. She also faces a felony charge of possession with intent to manufacture, distribute or deliver of THC, and a misdemeanor charge of possessing drug paraphernalia, all as a party to a crime.

Court records show Trumpy appeared in court October 18 and was freed on a signature bond. Hammer was released on $10,000 bail.

Mboge told the television station that Trumpy had agreed to help authorities make their case against Hammer.

“She actually met with them and was cooperating,” Mboge told WKOW-TV of a meeting between officials, Trumpy and her mother.

Hammer was convicted in 2017 in Nevada of unlawful possession, manufacture or disposition of an explosive or incendiary device, according to public records obtained by the television station.

Given that background and Hammer’s other criminal history, Mboge has questioned whether police should have provided protection for her sister

“They knew the man they were dealing with,” Mboge told the television station.

Green County District Attorney Craig Nolen declined to comment about what, if any, action law enforcement had taken in the case. He also said he did not personally speak with Trumpy, according to the television station.

“At no point have I had personal contact with her,” Nolen told WKOW-TV.

Trumpy and Hammer had lived together for about a year before he moved out approximately two months ago, the newspaper reports. There were multiple problems with the relationship, including involvement with police, Mboge told the Journal-Standard.

State child welfare authorities had also investigated because of concerns about the safety of Trumpy’s three kids, the sister told the newspaper.

“Things started going downhill,” Mboge told the Journal-Standard. “There was drug use with her children in the home. More and more things kept happening, and the kids started talking to their teachers.”

Among the other pending charges Hammer faces is domestic abuse, illegal possession of a firearm and possession of cocaine, according to court records.

Police found Trumpy’s rented pick-up truck Oct. 27 just 15 minutes from Hammer’s home on Oct. 27. Mboge told the newspaper she believes someone other than her sister left the truck there in an attempt to confuse investigators.

Hammer has not been charged in connection with Trumpy’s disappearance.

Since Trumpy went missing, loved ones have organized search efforts and held a vigil. Her sister hopes she will be found alive but acknowledges the gravity of the situation.

“That would be the greatest thing ever,” Mboge told the television station of the prospect that her sister is found unharmed. “But it’s just not likely.”

She expressed a bleaker view in an interview with the Journal-Standard.

“I have reason to believe (somebody) did away with her — buried her, threw her in a creek, something,” Mboge told the newspaper. “Melissa would never leave. The only thing that would keep her from us is death, or if she’s held hostage somewhere but I don’t think that’s a possibility. It’s been (more than) two weeks.”

A court proceeding is scheduled for Monday in Trumpy’s felony case, according to court records.

 call the Green County Sheriff’s Office at 608-328-9400 or the Carroll County, Illinois, Sheriff’s Office at 815-244-2635.