DNA test results may strengthen a claim of innocence by a man who spent years in prison for the murder of his ex-girlfriend.

Documents submitted to the Illinois Prisoner Review Board by attorneys for Alan Beaman indicate tests of a vaginal swab taken from murder victim Jennifer Lockmiller contained no DNA from Beaman. The tests also failed to turn up DNA from three other suspects in the case. However, the test did turn up DNA from two unknown males.

Assistant State's Attorney Pablo Eves said Thursday his office has received the results, which are being reviewed.

Beaman spent more than 13 years in prison after being convicted of stabbing and strangling Lockmiller. The Illinois Supreme Court vacated his conviction in May 2008, ruling prosecutors suppressed evidence about another suspect.