If there were any doubt about it, Assistant U.S. Attorney Judith E. Retchin made plain yesterday that the government wants a conviction against D.C. Mayor Marion Barry for perjury more than for any other charge.

Retchin made 48 references to lies and deception in her closing argument yesterday -- eight of them in the first minute. Her whole first hour of argument and her only new display chart for the jury were aimed at bolstering the three perjury charges. And her most direct attack on the defendant accused him of showing "his utter contempt and disdain" for the rule of law by lying to a federal grand jury.

What Retchin did not tell the jury, and what the jury is not permitted to consider, is that perjury is the only felony charge against the mayor, the only charge for which a prison term is virtually unavoidable upon conviction.

The perjury counts also were the source of Retchin's sharpest barbs. Twice, in an analogy that risked patronizing the city's chief executive, she went so far as to compare him to a child.

In grand jury testimony in January 1989, Retchin noted, Barry was asked whether he had given anything of value to Charles Lewis. "No," Barry replied, according to a transcript of his testimony. "If you are getting at -- I have never given Mr. Lewis any cocaine or any other drugs. Announce that right up front."

"If any of you have young children," Retchin told the jurors, "and you tell the child, 'Johnny, don't watch television' . . . and you say, 'Johnny, what are you doing?' and Johnny yells down, 'I'm not watching television.' Johnny couldn't even keep the lie inside him . . . . He had to blare out the lie.

"Mr. Barry was asked, 'Have you ever given Mr. Lewis anything of value?' That could have meant a car, it could have meant the use of a hotel room somewhere, but no, Mr. Barry couldn't even keep the lie inside him."

Later, discussing Barry's arrest at the Vista Hotel, Retchin repeated the comparison. One of the first things Barry told the arresting officers, Retchin noted, was: "I didn't have anything. I didn't, I didn't do anything."

"When he is caught red-handed like a child with his hand in the cookie jar . . . he tells a lie," she said. "The first thing out of his mouth, he tells a lie."

Retchin did her best throughout the argument to remove any inclination by jurors to forgive the alleged lies. Barry was clearly warned, she said, that his words might be used against him; he raised his right hand and swore to tell the truth.

His lies, she said, were numerous -- he denied even knowing Hazel Diane "Rasheeda" Moore -- and were based on a careful conspiracy with drug associates.

"Ladies and gentlemen," she said, "our government can't work well when the chief executive officer charged with enforcing all the laws goes into the grand jury and shows his utter contempt and disdain for the process."

For every stab she made at Barry, Retchin balanced it with a compliment to his lawyer, R. Kenneth Mundy. You may like Mundy, Retchin told the jurors in effect, but that does not mean you should believe everything he says -- or go easy on his client. "Some people are just born with a talent, a courtroom skill, a flare for oratory, and I don't pretend to compete with Mr. Mundy at all," she said. "There is no way I would win any contest like that. What I want you to do is not get caught up, not get caught up by the way Mr. Mundy says things . . . . Don't get distracted by smoke and mirrors."

For the first time in the eight-week trial, Retchin also sought to balance Mundy's courtroom charm with a small personal gesture of her own.

Retchin described how she often buys milk for an older neighbor who is unable to travel easily to the market. The woman, according to Retchin, would convey her need for milk without actually asking.

The overt aim of the story was to show how communication can sometimes be unspoken. But it also showed a warmer side of a prosecutor who usually projects a cool reserve in court.

Is this the kind of woman, the subliminal message asked, who would lead a ruthless conspiracy against the mayor? As usual, the jurors signaled no response.