Jury selection is set to begin Monday in the murder trial of a man charged with fatally shooting his ex-girlfriend and wounding her boyfriend in April of 2015.

Daniel Guajardo initially pleaded not guilty to first-degree murder and attempted first-degree murder in connection with the shooting, but changed his plea to not guilty by reason of mental illness in May.

Guajardo is accused of fatally shooting 26-year-old Janessa Spencer and wounding her boyfriend, Sam Cook, after breaking into Spencer's Cheyenne home.

Guajardo is facing life in prison with or without the possibility of parole if convicted.