BANGOR — The ex-girlfriend of a man accused of using Facebook to lure a 15-year-old to her death testified Monday that he confessed to committing the killing.

Prosecutors accuse Kyle Dube 21, of Orono, of using a phony Facebook account to kidnap Nichole Cable, of Glenburn, and kill her in May 2013. Dube and Cable knew each other, and he intended to stage a kidnapping of her so he could “find” her and look like a hero, police have said. She died of asphyxiation.

Dube’s ex-girlfriend Sarah Mersinger testified Monday that he told her he killed Cable, WZON-AM reported. She also said Dube covered up Cable’s body with leaves and sticks “so they couldn’t see her from the sky.”

Cable’s body was found in woods after an eight-day search.

Prosecutors have said DNA evidence ties Dube to Cable’s disappearance. His attorneys have said someone else killed the high school sophomore.

The murder and abduction trial began Feb. 23 and is expected to last a few more days. Detectives, friends and family members testified during the trial’s first week.