DARLINGTON, S.C. -- A Darlington County sheriff's deputy has resigned from his post for failing to follow procedure in a murder investigation and trying to cover it up.

Andy Locklair was the case officer on the murder of Michelle Haggadone. A body found in 2000 wasn't identified as Haggadone's until 2011, when a DNA match led investigators to a suspect.

Sheriff Wayne Byrd said John Boyer confessed to Haggadone's murder. Boyer was already in a North Carolina prison linked to two other murders.

Byrd said Locklair failed to process paperwork that would have allowed Boyer to be charged and returned to Darlington County to stand trial. The sheriff said after Boyer is released from prison in North Carolina, and serves time for murder in Tennessee, he will be returned for a trial.