A woman is being investigated for possibly disposing of Kelsey Berreth’s cell phone, NBC News has learned.
Details about the woman and how she is connected to the Berreth case are limited at this time, but it has been confirmed to NBC that she is a 32-year old nurse from Twin Falls, Idaho. That is about 35 miles from Gooding, Idaho, where investigators previously said Berreth's phone pinged on Nov. 25.
Berreth was last seen on Nov. 22, 2018 shopping at a Safeway store with her daughter. The Woodland Park mother wasn't reported missing until 10 days later, Dec. 2, when Berreth's mother Cheryl said she was having a difficult time getting ahold of her 29-year-old daughter.
Berreth’s fiancé, Patrick Frazee, was formally charged earlier this week with five criminal charges in connection to her disappearance. One of the charges includes first-degree murder, despite the fact that Berreth’s body has not been recovered yet.
Investigators said in previous press conferences they believe Berreth is no longer alive and that she was killed in her Woodland Park home.
“Investigators have recovered a number of items that make us suspicious that the crime did occur at Kelsey’s residence, and that’s why we have been coming back to her residence,” Woodland Park Police Chief Miles De Young said.
Frazee was the last person to see Berreth alive. De Young said the two had exchanged custody of their 1-year-old daughter on Thanksgiving.
The couple's 1-year-old daughter will remain in the custody of her maternal grandparents and child protective services.
Berreth's phone pinged in Gooding, Idaho on Nov. 25. She has family in Idaho and Washington, according to a missing persons bulletin for the case.
Twin Falls is about 35 miles southeast of Gooding.
The same day her phone pinged in Idaho, De Young said she sent a text to her employer and said she wouldn't be in the next week.
Twin Falls, Idaho police have since announced they are assisting the FBI, Colorado Bureau of Investigation and Woodland Park Police Department to prepare and serve several search warrants.
It's unclear if Frazee and the woman under investigation are connected in any way.
When Frazee was first arrested on Dec. 21, De Young told media that it was an "absolute possibility" that more arrests could be made.
On Friday, the parents of Berreth filed a wrongful death lawsuit against Frazee.
Berreth's parents are also suing for negligence. They say Frazee carried out physical, mental and emotional acts of violence against Berreth.
SUGGESTED VIDEOS | Kelsey Berreth case