A Washington County grand jury has indicted Dr. Steven C. Patterson of Whitneyville on a single count of gross sexual assault, Class A, stemming from an incident in April 1991.

Patterson, a pediatrician, allegedly committed a sexual act with a 10-year-old boy. He also was indicted on two separate charges of unlawful sexual contact with the same boy on March 30, 1991, in a dwelling and in an automobile.

Patterson said Thursday night that he was innocent of the charges. He said he couldn’t say more because his attorney had advised him not to say anything further, pending the trial.

The Washington County pediatrician said that his medical practice would remain open.