Nearly a month after Colorado mom Kelsey Berreth was last seen shopping with her 1-year-old daughter at a local supermarket on Thanksgiving Day, her fiancé has been taken into custody on a first-degree murder charge, police confirmed to The Daily Beast.

Patrick Frazee—Berreth’s fiancé and the father of her child—was arrested at his home in Teller County Friday morning and taken to Teller County Jail, a spokesperson for the Woodland Park Police Department said. He has been charged with first-degree murder after deliberation and solicitation of first-degree murder, charges that could carry a life sentence, police said.

While Berreth has yet to be found, authorities do not believe the 29-year-old mom is still alive. At a press conference announcing the charges, Woodland Park Police Chief Miles De Young said authorities have received information that is helping them narrow down the search for her body.

The arrest comes after investigators from the Colorado Bureau of Investigation, the Woodland Park Police Department, and the FBI went to Berreth’s home late Thursday night, authorities said, declining to give details on their findings.

Frazee’s attorney, Jeremy Loew, did not immediately respond to The Daily Beast’s request for comment.

The 29-year-old flight instructor was last seen on Thanksgiving Day, in the security footage of a local Safeway. In the video, Berreth places her 1-year-old daughter’s car seat in a shopping cart and heads inside the store.

Frazee told police he last saw Berreth that afternoon when he collected their little girl in a custody exchange. It’s unclear why Berreth didn’t spend the holiday with Frazee, though Berreth’s aunt posted on Facebook that she broke up with Frazee that day—a claim that hasn’t been confirmed by police or her family.

No one has seen Berreth since. On Nov. 25, her cellphone sent messages to her employer stating she would be off work the following week. The phone also texted Frazee, a cattle rancher, though the contents of the messages remain unknown.

The phone last pinged to a cell tower in Gooding, Idaho—nearly 800 miles away from Berreth’s residence in Woodland Park—that day at 5:13 p.m.

Berreth’s mother, Cheryl Berreth, who lives in Idaho, reported her missing on Dec. 2. “She’s not the kind that runs off,” Berreth said at a press conference eight days later. “This is completely out of character.”

Berreth and Kelsey’s only sibling, her older brother Clint, rushed to Colorado to search for her and launched a Facebook page to spread the word. They’ve mostly stayed silent on Kelsey’s relationship with Frazee and, in post and comments on the page, asked people to stop spreading rumors and speculation on the case.

On Dec. 14, police swarmed Frazee’s ranch in Florissant, about 34 miles west of Colorado Springs, in search of Berreth. The crew of 75 officers finished scouring the 35-acre property, where Frazee lives with his mother, the following evening.

“The search is complete and the property has been turned back over to the homeowner,” Woodland Park police said in a statement. “A backhoe was brought in to assist with the search as we continue to be as thorough as possible.”

But cops returned to Frazee’s ranch Tuesday, after employees at a waste management facility spotted him dumping trash and phoned police, KRDO reported. The workers reportedly said Frazee stayed in a white pickup truck while two men—who drove in two separate vehicles—unloaded garbage from a long trailer.

In a statement, the Woodland Park police force said officers were conducting a “routine follow-up from the search warrant.”

Loew released a statement of his own, saying investigators never asked his client to “voluntarily participate” in the 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 said. “Mr. Frazee will continue not to participate in any interviews with the media and instead focus on parenting the child he shares with Ms. Berreth."

Frazee nor his family has commented publicly since Berreth vanished.

Police Chief Miles De Young initially told reporters that Frazee was cooperative with their investigation, which he described as a “missing persons case.”

“There have been numerous questions about whether Patrick is a suspect or a person of interest. At this point, we are considering every possibility, and I’m not willing to jump to conclusions or label people involved in this highly complex investigation,” DeYoung told reporters at a press conference last Friday.

Berreth moved to Colorado in 2016 to be close to Frazee, her uncle told KOAA. Before moving, Berreth was a flight instructor in Washington state, where she grew up. It’s unclear how she met Frazee. “She’s a pilot. She knows a lot of people,” the uncle, Ed Stanfill, said. Stanfill added that Berreth didn’t move in with Frazee because he lives with his mother.

Meanwhile, Cheryl Berreth said everything seemed normal when Kelsey phoned her about a recipe on Thanksgiving morning. “No big Thanksgiving meal at her home or anything like that,” Berreth said in an interview with CBS News.

Berreth told NBC that her daughter and Frazee didn’t have a wedding date, and that “the economy” had prevented them from finding a place to live together.

When authorities entered Kelsey’s home, they found cinnamon rolls, which had cooled in the kitchen and her vehicles parked outside. Her cellphone and purse were gone.

Brandon Kindle, Berreth’s brother-in-law, previously told The Daily Beast that the Berreth family planned to spend Christmas in Idaho. “The family is extremely close. She and her brother spoke multiple times a week, as well as her mom,” Kindle said.

“We cannot even fathom the thought—what if we never find her?” he added.

The Woodland Park Police Department announced a $25,000 reward for information leading to Berreth’s location or safe return.