It's been 23 days since a young Colorado mother vanished -- and as investigators search the home of the last person who talked to her in person, police are calling her disappearance "suspicious."
Authorities executed a search warrant Friday morning at the home of Patrick Frazee, Berreth's fiancé and the father of her baby.
The search was still going as of Friday afternoon, Woodland Park Police Chief Miles De Young said.
Frazee was the last person to talk to Berreth face-to-face and is being asked to sit down with investigators, Young said at a Friday news conference.
The chief said Friday he wasn't willing to label individuals as suspects or persons of interest, but he added, "We are considering every possibility."
Earlier this week the chief told reporters Frazee was not a suspect.
Frazee's attorney, Jeremy Loew, said in a statement Friday that his client "continues to cooperate with law enforcement in the missing person investigation."
"Frazee was never asked to voluntarily participate" in Friday's search at his property, Loew said, adding, "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."
Frazee is declining to speak publicly and is instead focusing "on parenting the child he shares with Ms. Berreth," his attorney said.
ABC News' Bill Hutchinson contributed to this report.