Richmond County District Attorney Michael McMahon announced Thursday that the conviction of a man who served 23 years for a 1996 murder will be vacated.

The conviction of Grant Williams was vacated following a review that uncovered numerous credible witnesses who testified to his innocence, WABC-TV reported.

In addition, McMahon said the review determined that the identification process used by authorities did not meet modern standards or current best practices.

The reinvestigation found that throughout the original investigation, best practices for ensuring fair and impartial justice were not followed at several points nor the duration of the prosecution.

During the reinvestigation, over 35 fact witnesses were interviewed and investigators traveled to seven states and five different correctional facilities.

“Given the overwhelming amount of exculpatory evidence presented for the first time in this review, as well as a totality of the investigative circumstances in this case, which in several instances defy what we now accept as best practices, we now believe Mr. Williams to actually be innocent and conclude that our justice system failed him,” McMahon said.

(AP)