A 29-year-old Gaithersburg man pleaded guilty in U.S. District Court yesterday to a copyright violation in connection with the illegal sale of videotape copies of three motion pictures.

Michael Mansour Rashid was arrested Friday afternoon in the rooftop parking lot of the Safeway Store at 4310 Connecticut Ave. NW after he sold the films "Altered States," "Excalibur," and "On Golden Pond" to undercover D.C. police investigator William Cagney for a total of $100.

Police confiscated about 200 videotapes from Rashid's home during a search Friday night, as well as financial records that indicated he was earning about $1,000 a week renting films and selling copies of them. The copies were made from television showings of the films or were made from tapes borrowed from video clubs, police said. Rashid, who lives at 30 Anna Ct. in Gaithersburg, also employed at least one part-time worker, law enforcement officials said.

According to court records, Rashid has agreed to cooperate fully with federal officials, including the U.S. attorney's office and the FBI, in connection with an ongoing investigation into the illegal marketing of videotape films.

In exchange for Rashid's cooperation, the government has agreed not to bring charges against him for any other illegal sales of videotape cassettes uncovered during a D.C. police investigation over the last month.

Rashid was charged with criminal copyright infringement under a two-month-old federal law specifically designed to end the black market in video cassettes that has burgeoned since the introduction of home video equipment, according to Assistant U.S. Attorney Timothy J. Reardon III.

The charge, a misdemeanor, carries a maximum penalty of one year in jail, a $25,000 fine or both. U.S. Magistrate Lawrence S. Margolis, who accepted the guilty plea yesterday, scheduled sentencing for Sept. 13.

The D.C. police investigative services unit began an investigation after they were informed of an advertisement Rashid had placed in The Washington Post offering videotapes for rent and sale. Such tapes are available to consumers through legitimate video clubs that rent and sell tapes in compliance with copyright laws.