MINNEAPOLIS (AP) - A central Minnesota homeowner who killed two teenagers who broke into his home on Thanksgiving Day 2012 is claiming his life sentence is unconstitutional and he's asking to be released.

An attorney for 68-year-old Byron Smith of Little Falls filed documents Friday in federal court, claiming Smith's rights were violated when part of his trial was closed to the public.

Smith was convicted in 2014 of first-degree premeditated murder in the shootings of 18-year-old Haile Kifer and her 17-year-old cousin, Nick Brady. Smith was sentenced to life without parole.

Smith's attorney, Steve Meshbesher, says the shootings were self-defense.

He argues the courtroom was improperly closed to discuss admissibility of witnesses, depriving Smith of his right to a public trial.

The Minnesota Supreme Court has rejected that argument and others on appeal.