Kelsey Berreth was last seen Nov. 22 on store surveillance video shopping with her 1-year-old daughter

Fiancé Accused of Killing Missing Colo. Mom as Their Daughter, 1, Is Safe in Protective Custody

The fiancé of a Colorado mom who vanished on Thanksgiving Day has been arrested on suspicion of murdering the woman, who is still missing but is presumed dead, authorities announced Friday.

Patrick Frazee, 32, was detained without incident on suspicion of first-degree murder and solicitation to commit murder in the first degree in the death of 29-year-old Kelsey Berreth, the Woodland Park Police Department said in a press release. Formal charges will be filed in the days ahead.

Get push notifications with news, features and more.

At a Friday press conference, authorities said more arrests in the case are possible and that cell phone records and other data led to Frazee’s arrest for the alleged crime, which they believe may have occurred in Berreth’s residence.

Police have not revealed a possible motive.

Berreth, a pilot instructor from Woodland Park, was last seen in public Nov. 22 on store surveillance footage that showed her walking into a Safeway market with the 1-year-old daughter fathered by Frazee, to whom she was engaged.

Her mother, Cheryl Berreth, reported her daughter missing 10 days later, on Dec. 2, provoking early questions about why Frazee had not alerted police previously.

Image zoom Kelsey Berreth Facebook

Last Friday, investigators searched the home and 35-acre property of Frazee, who lives in Florissant, about 15 miles west of Woodland Park, according to ABC News, the Denver Post and local TV station KMGH.

Image zoom Patrick Frazee Woodland Park Police

Frazee, who did not live with Berreth, told police that he’d not seen her since that Thanksgiving when they met up so that Berreth could hand off their daughter, Woodland Park Police Chief Miles De Young previously told the media.

The couple’s daughter had been staying with Frazee after Berreth disappeared but is now in protective custody and will soon be reunited with Berreth’s family, authorities announced.

Family member JoDee Garretson, who is first cousins with Berreth’s mom, tells PEOPLE, “I’m just relieved. I saw that [the girl] is safe. I don’t know where she is — but I did see she’s safe.”

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

Image zoom Facebook

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.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Video obtained by ABC reportedly shows Frazee’s arrest.

In a statement to PEOPLE at the time that Frazee’s property was searched, his attorney, Jeremy Loew, said: “Mr. Frazee was never asked to voluntarily participate in this search. We encourage law enforcement to take whatever steps it deems necessary to find Kelsey Berreth and to be able to exclude Patrick Frazee as a possible suspect in this missing person investigation.”

Loew did not immediately return PEOPLE’s call and email for comment.

Investigators said the court has sealed affidavits in the case, which will likely remain sealed for up to 30 days, or until investigative leads can be followed up on.