A San Mateo County deputy sheriff accused of pointing a gun at a custodian in a Redwood City courtroom in April explained to investigators that he did have his gun out of its holster, but that he was checking the gunsight, prosecutors said.

Deputy Andy Mar, 50, is facing a charge of misdemeanor brandishing of a firearm, District Attorney Steve Wagstaffe said.

Prosecutors filed the charge on May 7 and arraignment is set for Friday, May 22, at 8:30 a.m. in Redwood City Misdemeanor Court.

Mr. Mar has been on administrative leave since April 15, according to Deputy Rebecca Rosenblatt of the Sheriff's Office.

Mr. Mar was working as a temporary bailiff in a seventh-floor courtroom on April 13, according to prosecutors. Also in the courtroom, which was not in session, were a custodian, a court clerk and a court reporter, Mr. Wagstaffe said. At the time of the incident, the custodian and the clerk were talking at the clerk's desk, prosecutors said.