JOSEPH Michael Lopez who was arrested on Friday for the shooting death of 19-year-old Colorado teenager Natalie Bollinger said he answered an ad she put on Craigslist for someone to kill her.

Denver 7 reports that Mr Lopez, 22, told police that shortly after Christmas he came across a bizarre ad while looking through the ‘Woman seeking men; section of Craigslist which was entitled ‘I want to put a hit on myself’.

He says after more than 100 texts he agreed to meet and kill her for a fee.

The affidavit states that he picked her up from her apartment on December 28 and that she said she wanted to be killed “on her knees ... executed from behind”.

Mr Lopez says Bollinger brought her own gun.

He says he tried to talk her out of it but she was determined and said she was having issues with her boyfriend.

Her boyfriend, who reported her missing, had told officers his pistol was also gone from his house.

Mr Lopez says Bollinger “knelt down on the ground and that he knelt down along her left side and slightly in front of her.”

He then claims they both said a prayer, he got up, closed his eyes and shot the teen. He took off with Bollinger’s purse and the gun.

Bollinger’s autopsy shows she also had a high dose of heroin in her system.

Family and friends had told police that Bollinger had a history of suicidal thoughts but others said she seemed happy of late.

Legal experts told Denver 7 that even if Mr Lopez’s story checks out it is still murder. However, he might receive a shorter sentence if Bollinger did ask for assistance.

Police had initially suspected a man named Shawn Schwartz, 42, who Bollinger had accused on Facebook of stalking her.

Police have since dismissed Schwartz’s involvement.

If you are experiencing mental health issues or suicidal feelings contact Lifeline on 13 11 14 or BeyondBlue 1300 224 636. If it is an emergency please call 000.