Like most people. Billy Flynn has vivid memories of his first sexual encounter. Unlike most, Flynn, a shaggy-haired teenager with a wisp of a mustache, found himself obliged to recount his experience in court last month. Sitting tensely in the witness box at Rockingham County Superior Court in Exeter, N.H., Flynn described how a year earlier, as a sophomore at nearby Winnacunnet High School, he had visited the school district's media director, Pamela Smart, at her condo one night when her husband was away. Smart, then 22 and an adviser of an alcohol-and drug-awareness program at Winnacunnet, sat down with him to watch the steamy film 9½ Weeks on her VCR. Then she led Billy upstairs, where she did a striptease like the one performed by Kim Basinger in the movie. Then, to the thump of Van Halen's "Black & Blue," they had sex. Later, returning to the 9½ Weeks theme, Billy said he rubbed ice cubes along her body the way Mickey Rourke did to Basinger. "I was kind of shocked," Flynn later testified. "It's not every day that a 15-year-old kid gets this 22-year-old woman who is very attractive to say that she likes him."

It's even rarer that she gets him to murder her husband, which is why the televised two-week trial of Pamela Smart left viewers all over New Hampshire mesmerized. Authorities charged that Smart had lured Flynn into her bed and then persuaded him to recruit three friends-Patrick Randall, 17, Vance Lattime, 18, and Raymond Fowler, 19—to kill her husband, Gregg, a 24-year-old insurance salesman, on May 1, 1990. Using testimony by Flynn, Randall and Lattime, all of whom cut deals with the state, prosecutors laid out a chilling scenario of a marriage gone homicidally wrong. As the sensational trial unfolded, video stores around New Hampshire reported that 9½ Weeks had suddenly become one of their hottest-renting cassettes.

Smart, a former high school cheerleader and a graduate of Florida State University, had met Flynn in the fall of 1989 at Winnacunnet, where they cultivated their mutual interest in heavy-metal music. Before long the two were passing love notes in school and having sex in her Honda CRX. Flynn testified that not long after they became lovers, Pam had broached the subject of killing Gregg. She told Flynn that she and her husband were not getting along and that he physically and verbally abused her. She feared that if they divorced he would get all their possessions, including the furniture and their Shih Tzu, Halen—named for the rocker. Some of Gregg's family speculated, however, that Pam's real disenchantment with the marriage stemmed from the fact that Gregg had cut back on his partying and rock music and had even, gawd, started to mature.

Whatever the roots of her marital problems, Pam emerged at the trial as the epitome of the practical young murderer. Her plan was for Flynn and Randall to jump Gregg when he got home from work, kill him and make the job look like a botched burglary. In their testimony, the two boys recalled how Pam had warned them not to use a knife on her husband out of concern that his blood would get all over the furniture. She also insisted that Flynn put the dog, Halen, in the basement before doing away with his master. "She told Bill not to kill Gregg in front of the dog because it would traumatize the dog," testified one prosecution witness. Driving with the boys prior to the killing, Pam tried to figure out how to behave when she came home and found Gregg dead. "She just kept asking us how she should act," said Lattime. "She didn't know whether to scream, run from house to house or call the police. We told her just to act normal."

Flynn and Randall got to the Smarts' Derry, N.H., condo around nightfall. Dressed in dark clothes, their fingertips wrapped in Scotch tape to be sure they wouldn't leave fingerprints, and wearing latex gloves, the pair entered the apartment through the basement. When Gregg came home around 9 P.M., Randall testified, they pounced on him by the front door. Randall grabbed him by the hair, slammed the struggling victim against the wall, then forced him to his knees. He demanded that Gregg hand over a ring he was wearing.

"At first I thought it was just a normal gold ring," Randall testified. "But it turned out to be a wedding band."

"And what happened at that time?" prosecutor Paul Maggiotto asked.

"He told me he wouldn't give it to me."

"Why not?"

"He said his wife would kill him."

Despite Pam's admonition, Randall had intended to use a butcher knife to slit Gregg's throat; now he couldn't go through with it, Standing behind Gregg, Flynn pulled out a .38-caliber Charter Arms revolver that they had taken from Lattime's father and which Flynn had deliberately loaded with hollow-point bullets, which are especially deadly. Flynn said he held back for a moment after aiming the gun at Gregg's head. "A hundred years it seemed like," he testified in a quavering voice. "And I said, 'God forgive me.' " When the prosecutor asked what happened next, Flynn, crying and sniffling, paused seven seconds before replying: "I pulled the trigger."

Ultimately the killers were tripped up by a host of factors. A little over a month after the murder, Vance's father heard from a friend of the boys that one of his guns was the murder weapon. He turned the revolver over to police, who matched the ballistics. At that point it didn't take long to establish Flynn's link with Pam. Investigators also discovered that Pam's student aide, Cecilia Pierce, 16, knew about the crime. To get the evidence they needed, they convinced Pierce to wear a wire while chatting with Smart.

When played in court, the recordings, complete with Smart's undeleted expletives, made her sound anything but a grieving young widow. When Pierce asked her what she should tell police, Smart brusquely replied, "You're better off lying." Discussing the possibility that Lattime might confess to the police, Smart sketched out her defense. "That's when I'm going to be in trouble," she said. "That's when I'm going to get arrested, but I can probably get out of it because they are not going to have any proof, ya know." Pam, who had told friends that she wanted to be a television interviewer like Barbara Walters, pointed to her "professional reputation and the course that I teach" as reasons why authorities wouldn't take Lattime's word over hers. "They are going to believe me," she said.

When Smart took the stand in her own defense, she seemed only to dig herself in deeper. She claimed that her banter with Pierce was all part of a calculated "game," and that she was really trying to conduct her own investigation into the murder. Nor did it help that in her testimony Pam showed virtually no emotion, even when describing her discovery of Gregg's lifeless body, thereby seeming to confirm the prosecution's depiction of her as a killer with no conscience. "Cold, calculating, manipulative, self-centered, totally unfeeling for anybody but herself," says Derry police Capt. Loring Jackson, who supervised the investigation.

Pam's lawyers denounced the state case as "toxic soup" and characterized Flynn and his cohorts as deranged "thrill killers" who had murdered Gregg Smart to eliminate him as a romantic rival. But in the end the jury of seven women and five men needed only 13 hours of deliberation to return their guilty verdict. Judge Douglas R. Gray imposed the mandatory sentence for an accomplice to first-degree murder: life in prison without parole. (As part of their plea bargain, Flynn and Randall agreed to serve at least 28 years; Lattime would serve a minimum of 18. The boys are also expected to testify against Fowler, who has pleaded not guilty.)

Gregg's parents, Bill and Judy Smart, were visibly anxious as the jury filed in. With the pronouncement of each verdict, cries of joy erupted from the first row, where they sat with other family members, all of them holding hands. "In my life and 25 years experience in the insurance business," Bill said later, "I have never met such a cold person [as Pam]." For their part, prosecutors and police investigators expressed satisfaction that out of the tawdry mess had come some measure of justice. "I think life in prison without the possibility of parole for this young lady is very fitting," said Captain Jackson. "I wish her a long life."