LINCOLN, Neb. (AP) — The Nebraska Supreme Court has affirmed the first-degree murder conviction of a western Nebraska man sentenced to life for killing his girlfriend.

Craig Johnson was sentenced last year for the Dec. 11, 2011, killing of 42-year-old April Smith. Smith was found bound, strangled, beaten and stabbed on her living room floor in the home she and Johnson shared eight miles west of Sidney.

Johnson argued on appeal, among other things, that his trial judge should not have allowed inconclusive DNA testing found at the murder scene into evidence.

On Friday, the high court agreed that the DNA evidence should not have been allowed, but found the error harmless, as prosecutors had more than enough other evidence — including other DNA evidence — to convict Johnson.