"Deep Throat" was showing in two Baltimore locations yesterday morning -- at a North Avenue movie theater and in the courtroom of Judge James W. Murphy.

Behind locked doors, the Baltimore Circuit Court judge, the opposing lawyers, a few clerks and a few newsmen watched the 62-minute film which the Maryland State Board of Censors has banned.

After the film, Judge Murphy had no comments on its artistic merits, but scheduled a 10 a.m. hearing tomorrow. Under Maryland law, appeal on a film rejected by the censor board is automatic, and must be held within two days of the judge's screening.

At the North Cinema, at 7 East North Avenue, the movie was shown continuously starting at 10:30 a.m.

Although the Vice Squad did not raid the show until 5 p.m. -- seizing the fourth copy of the Linda Lovelace movie -- the police were expected all day.

Persons who purchased a $6 admission ticket were instructed to stay in their seats "if there's any excitement."

"Hold onto your tickets, if there's any excitement, stay cool, stay in your seats and we'll give you your money back," they were told by the ticket taker.

Richard T. Slater, the day manager, stood in the lobby, watching the patrons and keeping an eye out for the police, who he said he expected "any minute."

The woman who sold popcorn and candy asked the customers to sign several petitions.

The first was a mimeographed sheet that asserted adults have a right to see anything they want.

The second was a sheet which listed people's names, addresses and telephone numbers.

At first, the popcorn woman was secretive about the list, whispering its meaning to the patrons.

"Is it a mailing list?" she was asked. "Yeah, sure," she replied, laughing.

But eventually, Mr. Slater said, "Look, I'll be honest with you.

"It's a list of the people here, who agree they'll go to court to show they think this movie ought to be shown."

Mr. Slater said he had been instructed not to speak with reporters, but he showed them a piece of paper with the name "Bill Seekford" scrawled on it, with two telephone numbers.

William E. Seekford, a Towson lawyer said he had not seen the film before its court showing yesterday.

The theater's manager, A. Kelly Magnum, 36, of the 800 block Furnace Branch Road in Glen Burnie, "started out showing the film as a regular distribution," Mr. Seekford said.

"But now it's become a matter of principle," the lawyer explained. "It's being shown in a selective showing for adults only. It's not being foisted on anybody.

"The way the censor board and the police are acting, it's putting everyone at odds."

The police have now raided the movie house four times, each time confiscating the X-rated film and unsuccessfully searching the projection room for extra copies. Each print is reported to rent for over $1,000.

"I wonder how long this thing is going to go on," said Lt. George E. Andrew, head of the Vice Squad, on the third raid Tuesday night.

But yesterday, Lieutenant Andrew spent part of his day closeted with lawyers from the state's attorney and state attorney general's offices.

Shortly before the 5 p.m. raid, Francis B. Burch, the State attorney general, said his office was launching a "three-pronged attack" on the film.