Richard Craig Smith, found not guilty of violating espionage laws by a federal jury Friday night, sat in the sunny back yard of his lawyer's office yesterday, surrounded by jubilant family members and friends, and said the first thing he wants to do "is go home and hold my kids."

The 42-year-old father of four from Bellevue, Wash., described the two years since his arrest in April 1984 as "miserable."

For a time, Smith said, FBI surveillance was so intense that he and his family were under "house arrest." FBI agents parked outside his house around the clock, he said, "and they would have parked inside the house, if they could have."

But now there is palpable relief and joy for the former Army counterintelligence specialist, his wife Susan, and his parents, Dorothy and Hyrum Smith, as they set out yesterday for a trip to the countryside to celebrate the end of his five-day trial in U.S. District Court in Alexandria. The mood was giddy, and there was even some black humor about the trial.

"This is Craig's lover," Susan Smith quipped as she introduced her husband's former secretary, Mavis Nelson, to a visitor. "I'm just the wife, the boring part of the family," she added as everyone laughed.

In an attempt to shake Nelson's credibility when she testified for the defense, Assistant U.S. Attorney Joseph J. Aronica had asked if it were not true she and Smith were lovers. Nelson denied it and Smith's lawyer, William B. Cummings, called the prosecutor's question "a scurrilous, low blow."

Aronica said Friday that he would not have raised the issue if he had no basis for doing so, but he would not elaborate.

The jury of nine women and three men, deliberating six hours, found Smith not guilty of violating espionage laws for disclosing the identities of six double agents to the Soviets for $11,000. He had faced a life sentence if convicted.

Smith, a sparely built man with a mustache, admitted that he had passed classified information to a Soviet official in Tokyo in meetings in 1982 and 1983. But he testified that he did so as part of a Central Intelligence Agency double-agent operation to infiltrate Soviet intelligence.

"I've sold secrets to the Soviet Union as part of an American operation," he told the jury, adding that he followed CIA instructions "to the letter."

He said that he had not told FBI agents during interviews stretching over a 10-month period that he was working for the CIA because a CIA agent had told him "to keep your mouth shut."

Smith, a graduate of McLean High School, portrayed himself yesterday as a spy left out in the cold, a scenario he knew was always possible from his previous job. From 1973 to 1980, Smith worked at the Army's Intelligence and Security Command, where his main responsibility was inventing plausible "cover stories" for U.S. double agents.

The CIA had determined that he was "expendable," Smith charged yesterday, in order to cover up an embarrassing situation involving the CIA agent who he claimed ran the Tokyo double-agent operation.

The agent, Charles Richardson, testified that he had been forced to resign because of questionable financial dealings with a CIA front company in Hawaii. But Richardson testified that he did not know Smith.

Eight FBI agents testified that Smith told them he had divulged classified information to the Soviet official.

One agent said that Smith admitted making an unsuccessful attempt to offer secret information to Soviet officials in San Francisco in 1980, a year before he said he was recruited for the Tokyo operation. A CIA employe testified that the agency had no records of the two men who Smith said had recruited him.

Prosecutor Aronica said that Smith sold the information because he was deeply in debt and had fabricated the CIA link after his arrest, when he saw news reports about the CIA front company in Hawaii.

"The idea that the CIA would have [Smith] working as a double agent and that another agency of the same government would bring him in here to prosecute him is preposterous," Aronica told the jury.

Aronica, who would not comment on the verdict Friday night, could not be reached for comment yesterday.

Asked what had been going through his mind most of the trial, Smith said he was thinking, "Why can't we just tell the jury what we know the truth is and get this thing done with?"

His trial was delayed for nearly two years because of legal disputes over classified information that he wanted to introduce as evidence.

Ultimately, he said, the 4th U.S. Circuit Court of Appeals in Richmond issued a ruling that permitted him to bring in only "about 1 percent" of the classified material he had sought to use.

Smith attributed his acquittal to several factors, among them the efforts of his lawyers, Cummings and A. Brent Carruth, and the fact that U.S. District Judge Richard L. Williams "was willing to be fair to the very maximum extent of the limitations placed on him" by the higher court's ruling.

Smith said that he had "told the truth" and that, in addition, there was "an awful lot of faith and prayers." Smith, who is a Mormon, said that he "had been helped materially and spiritually . . . by members from all across the country," many of them people he had never met.

With his ordeal behind him, Smith said, he plans to return to Bellevue, a suburb of Seattle, where he has been working for an advertising firm. He added that he plans to "explore some business opportunities."