An attorney defending a Howard County police corporal accused in two domestic assaults wants to use charges his estranged wife filed against previous partners - domestic complaints that were later dropped - to attack her credibility during the officer's trial next month.

Clarke F. Ahlers, who represents Cpl. Michael K. Williams in the cases - one involving a gun - asked Howard Circuit Judge Dennis M. Sweeney yesterday to allow him to question Elizabeth M. Williams, 33, about what he alleged were "perjurious charging documents" that he said she has filed against ex-boyfriends.

But a Carroll County prosecutor, who is specially assigned to the case, said she would contest Ahlers' request and has lined up a domestic violence expert to detail the psychology of domestic abuse if the old cases are addressed at trial.

Sweeney did not hear arguments on the issue yesterday. A second motions hearing is scheduled Aug. 23.

But Ahlers' motion set the stage for what is expected to be a contentious trial.

Michael Williams, 41, is accused of two separate assaults on his estranged wife last year - one Aug. 26 and the other Oct. 20.