James Dutton Smith was driving from his Kensington home to his job in Virginia last Friday morning when a Montgomery County police car, dome lights awhirl, forced him to the side of the road. Another car pulled up behind him and two detectives scrambled out, holding their badges aloft.

"I don't know how to tell you this," said one of the detectives to the 38-year-old electrician. "But you're supposed to be dead."

In the next few minutes, the detectives informed Smith that they are seeking his estranged wife and a former boarder at their suburban red brick house on charges that for the past month the pair had plotted to murder him and reap some $30,000 in insurance money.

And they added, but for the grace of a hit man who got cold feet and told a uniformed officer about the plot, enabling police to substitute an undercover agent as a new hit man, that sunny April morning might have been Jim Smith's last.

Shortly thereafter, a few miles away, police arrested 38-year-old Margaret talbot smith and 27-year-old Martin J. Gutierrez.

Gutierrez, who is the godson of Antonio Somoza, and whose father was a consular official under the deposed dictator at the Nicaraguan Embassy here, was charged with two counts of soliciting murder and one count of conspiracy to commit murder. He is being held pending a bond hearing at the Montgomery County detention center.

Margaret Smith, who has been separated from her husband for a year and had begun divorce proceedings, was charged with conspiracy to commit murder and was held at the detention center without bail.

His wife and the former boarder, who had a "mother-son relationship," would reap upwards of $30,000 in insurance payments, according to police.

Margaret Smith's lawyer, Nelson Rupp, said his client was in total shock. Gutierrez's arrest Friday at the Holiday Inn in Chevy Chase where he worked for 14 months as a desk clerk left many of his coworkers stunned.

"I'm absolutely flabbergasted," said innkeeper Stanley Craig. "He was conscientious as hell. It's so incongruous with our perception of the guy. Everybody else is [flabbergasted] too."

Gutierrez, a former student of hotel management at Montgomery College, moved into the Smith's house a year ago.

His father, the Nicaraguan Embassy's air, naval and military attache for nine years under Somoza, had lived a few blocks away on 10705 Torrance Dr. In 1976 the diplomat left his post, eventually to become Nicaragua's ambassador to Japan. And one day, Smith remembers, his wife "brought Martin home."

The electrician fixed up a room in the basement for the slight soft-spoken foreigner.

"He had a mother-son relationship [with Margaret Smith]," Smith recalled.

Smith's wife eventually left him to move in with another man in a nearby house. Enmity mounted between Smith and his boarder until about two months ago when the electrician threw the Nicaraguan out of the house.

Last month, according to police, Gutierrez walked into a pornography shop on 13th Street in the District and was introduced to a 32-year-old "street man" who'd just done 18 months in jail and was floating aimlessly between Maryland and the city.

Gutierrez, according to police, offered the street man the job of killing James D. Smith.

The man mulled it over for nearly a month, police said, and then confided with officer John Beane on April 6.

"Something's been on my mind for four weeks," he said, and went on to relate the bargain the Nicaraguan had allegedly proposed: $200 in cash for earnest money and $8,000 when the murder, which had to appear to be an accident, was completed.

The officer and his informant rode over to the Silver Spring police station and called in detectives.

Two days later, in the parking lot of Silver Spring Safeway, the street man introduced Gutierrez to an undercover agent, who was wired for sound.The discussion that ensued touched on various methods of causing an accidental death, including electrocution and animal poisons, but the parties settled on a hit-and-run accident.

On April 10, the phony hit man met again with Gutierrez in the Safeway parking lot and received pictures of James Smith, a map of the route he took to Dynaelectrics in Virginia each day where he worked. He also got an $8,000 check postdated for June.

The agent handed Gutierrez a key to a safe deposit box at Suburban Trust bank in Rockville where the check would be held until the transaction was complete.

According to one police officer, "Gutierrez kept referring to Mrs. Smith. We knew she was aware of what was going on."

On the Friday the murder was supposed to take place, police said, the undercover agent called Margaret Smith and she allegedly told the agent that she knew what the man planned to do, where he could find Smith and that she had an alibi.

Police arrested her just after she had dropped off one of her children at the Oakland Terrace Elementary School.

And over at the Chevy Chase Holiday Inn, they swooped down on Gutierrez. As lawyers and friends tried to sort out the motives of the pair, many of the young Nicaraguan's acquaintances groped for insight.

"That's a helluva note," said innkeeper Craig, who remembers that the only time Gutierrez spoke of his personal life was when he voiced concern that his father might be extradited from the U.S. with the change of regimes in Nicaragua. "That's really a helluva note. We're really strange creatures, aren't we?"