Colorado authorities arrested a man on Thursday in connection with the death of a Broomfield teen girl, but he claims that the victim posted an online ad and posing as a hit man, arranged to pay him to take her life.

As CrimeOnline previously reported, deputies with the the Adams County Sheriff’s Office booked Joseph Michael Lopez, 22, into jail earlier this week on suspicion of first-degree murder. According to a coroner’s report, 19-year-old Natalie Bollinger, who had been missing since December, was shot in the back of the head.

Bollinger disappeared on December 28, shortly after posting on social media that a man was stalking her. The man, identified as 42-year-old Shawn Schwartz, was later cleared.

ABC’S Denver7 reports that authorities indicated that after detaining Lopez, they interrogated him and he slowly began talking about what happened on the night Bollinger died. According to an arrest affidavit, Lopez said Bollinger placed an ad under Craigslist’s “Women seeking Men” section and took out a “hit” on herself.

After a lengthy text message exchange with the teen, Lopez said he picked her up on December 28 and they drove around while Bollinger reportedly told him she wanted to be killed “on her knees… executed from behind.”

Lopez reportedly told police that he tried to talk Bollinger out of it, but she insisted she wanted to die, according to the arrest affidavit. He then said he changed his mind about going through with the shooting and dropped her off at her apartment, but authorities informed him that they tracked his GPS to the location where the teen’s body was found. Lopez then confessed to the killing, authorities stated.

The suspect is being held at the Adams County Detention Center. So far, bond has not been set.

Check back with CrimeOnline as additional details become available.

[Feature Photo: Natalie Bollinger/Handout & Joseph Lopez/Police Handout]