The lawsuit, filed in federal court, seeks unspecified damages from Patrick Frazee in the presumed death of Kelsey Berreth

The parents of a missing Colorado woman who is presumed dead has filed a wrongful death suit against her fiancé, who has been charged with murder.

Kelsey Berreth, a 29-year-old flight instructor from Woodland Park, hasn’t been seen in public since Thanksgiving, when surveillance video captured her and her daughter entering a local supermarket. In late December, authorities arrested her fiancé, Patrick Frazee. He faces two counts of murder and three counts of solicitation to commit murder.

Berreth’s parents, Cheryl and Darrell Berreth, filed the lawsuit on Friday in Colorado’s federal district court. The lawsuit, which was obtained by PEOPLE, seeks unspecified damages against Frazee for Berreth’s presumed death.

Frazee and Berreth have a 1-year-old daughter, Kaylee.

While Teller County investigators have yet to detail the specific allegations that led to the solicitation counts, it likely means prosecutors think Frazee allegedly solicited an individual three times or three people on three separate occasions as part of an alleged murder plot.

The alleged solicitations occurred between Sept. 1 and Nov. 1, 2018, according to the charging documents, which were obtained by PEOPLE.

According to the charging documents, prosecutors filed two murder counts because they have two theories about how the presumed killing may have taken place: either Frazee killed Berreth by himself, or he and someone else allegedly tried to rob Berreth before she was killed.

Kelsey Berreth
Patrick Frazee, Kelsey Berreth and the couple's infant
| Credit: Facebook

Frazee, who did not live with Berreth, told police that he and his fiancée met up that same day so that Berreth could hand off their daughter to him.

Berreth’s mother, who lives out of state, reported her missing 10 days later, on Dec. 2, 2018.

Kelsey Berreth
| Credit: Facebook

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Frazee remains in police custody without bond. He has not yet entered pleas to the charges, and his criminal attorney could not be reached for comment. It is unclear if Frazee has representation in the civil case.

Authorities are investigating a second person — an Idaho woman — in the case. They believe she might have helped dispose of Berreth’s phone, multiple outlets report.

Three days after Berreth apparently vanished, her mobile phone pinged on a cell tower near Gooding, Idaho, nearly 600 miles from her home, police have said.

That same day, texts from the phone of Berreth were sent to her employer, Doss Aviation, saying she would not be at work for the next week.

The status of the couple’s relationship remains something of a mystery, with relatives saying Berreth had ended the engagement weeks before vanishing. Others have claimed the couple split the day of the alleged killing.

Attorneys for the Berreth family did not immediately return PEOPLE’s call for comment.