A Shasta County man has entered a guilty plea for trying to kill his ex-girlfriend. On September 14th of last year, 44-year-old Joshua Carlson lay in wait for her when she came to his home to pick up some of her things. She was standing on the porch when he shot her in the chest through his kitchen window. She survived her wound. Carlson told detectives that he had prepared for the ambush the night before by loading his revolver and running through different scenarios in his head. He said he was surprised at how relaxed he was when he shot her. Carlson will be sentenced to 21 years in state prison.