But as they were on the phone, the conversation suddenly stopped.
"Her mother heard the attack going on," Salt Lake City Police Department spokesperson Sgt. Brandon Shearer said. "And then the phone went dead."
The incident was part of what police called a "very violent and brutal attack" in the home, Shearer said.
Once the phone went dead, Bagshaw's mother contacted a neighbor as well as police. Officers called to do a welfare check at the residence and discovered the teenager dead inside the home, according to a police watch log.
It was unclear whether the attacker was waiting inside the home before Bagshaw's arrival. Police are not yet announcing Bagshaw's official cause of death, according to Shearer.
Authorities identified Shaun French, 24, as a suspect in Bagshaw's killing. He was taken into custody on Wednesday.
Today OCSO and CSP stopped and arrested Shaun French age 24 at Hwy 50 / CR 13. French was wanted out of Utah on sex assault charges. Thanks to @CSP_LaJunta and @PuebloCountySO for assistance. @OteroSheriff pic.twitter.com/nOpa2guON5— Otero County Undersheriff - Colorado (@CountyOtero) May 9, 2018
"At this point he is being held in Colorado until extradition can take place and he is brought back to Utah," Shearer said.
French was known to the family, Shearer said, adding that he had a previous relationship with the victim and lived with her briefly.
He was not living with her at the time of the attack. Authorities said an investigation is underway to determine the timeline of the relationship and the motive for the killing.
French also has an active felony warrant out for three counts of unlawful sexual acts with a minor, stemming from previous contact with the victim, police said.
One of the reasons the felony warrant was obtained was to help facilitate French's extradition back to Utah in the event he was apprehended out-of-state, according to Shearer.
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