UNDATED (WSAU) Milwaukee County prosecutors will review 2,100 murder convictions over the last 18 years, to see if new D-N-A tests could cast doubt on those outcomes. That’s after a judge ordered another inmate to be freed yesterday.

38-year-old William Avery was the third prisoner to wrongly do time for a homicide which new D-N-A tests linked to alleged serial killer Walter Ellis. Avery spent five years behind bars for the 1998 strangulation death of 39-year-old Maryetta Griffin. He was convicted in 2005, and was sentenced to 40 years. Last month, Avery asked prosecutors to test Griffin’s D-N-A, saying it would prove his innocence. That test turned up Ellis’s D-N-A. He’s scheduled to stand trial in October in the murders of seven other Milwaukee women over a span of 21 years.

Officials say the police should have identified Ellis from the start in its investigation of the Griffin murder. But he was among 17-thousand Wisconsin convicts who escaped a requirement from 2000 that he submit his D-N-A to a statewide police data-base. A state Corrections’ Department task force has been trying to catch up with those criminals since last year – and they’ve received over seven-thousand samples so far.