CONCORD, N.H. —When 16-year-old Billy Flynn gunned down the husband of his high school instructor and lover, Pamela Smart, in 1990, the trial became an instant tabloid sensation. Its lurid details aired gavel-to-gavel on television years before the O.J. Simpson spectacle and spawned movies and books.

Twenty-five years after Gregg Smart's killing, Pamela Smart remains in prison serving life without the possibility of parole and Flynn makes his first bid for parole Thursday, his 41st birthday.

Flynn pleaded guilty to second-degree murder and testified in Smart's 1991 trial that she threatened to break up with him if he didn't kill her husband. Flynn was sentenced to 28 years to life in prison, minus credit for pretrial incarceration. Here's a look at some key details in the case:

THE PLOT

According to trial testimony, Smart was 22 and one of Flynn's instructors in a self-awareness program at Winnicunnet High School in Hampton when she seduced the 15-year-old Flynn. She told him she needed her husband killed because she feared she would lose everything, including her dog and furniture, if she divorced Gregg Smart as their wedding anniversary approached.

Flynn said he and three cohorts bungled an attempt to kill Smart in April, when they got lost on the way there. But on May 1, 1990, he and 18-year-old Patrick Randall entered the Smarts' Derry condominium and forced Gregory Smart to his knees in the foyer. As Randall held a knife to the man's throat, Flynn fired a hollow-point bullet into his head.

To this day, Pamela Smart denies knowing about the plot. But the state's star witness, a teenage intern in whom Smart confided, secretly recorded her after the killing saying, "If you tell the (expletive) truth, you'll send me to the slammer for the rest of my (expletive) life."

Smart was convicted March 22, 1991, of being an accomplice to first-degree murder, conspiracy and witness tampering. Randall got 28 years to life; he comes up for parole in April. Two other teenagers served prison sentences and have been released.

SENSATIONAL TRIAL

Smart's trial was the first in the country to be televised nationally from start to finish, her trial lawyer, Mark Sisti, said ruefully.

"Her trial turned into the ultimate daytime TV drama, and the witnesses were dressing up for it and performing rather than testifying," Sisti said.

Hers was also one of the first high-profile trials involving a teacher-student sex affair.

Stories of the trial and Flynn's testimony about their affair were picked up internationally, and cameras caught every graphic image and detail.

"We're a voyeuristic society," said veteran trial lawyer and University of New Hampshire School of Law professor Buzz Scherr. "We like looking at other people's dirty laundry."

And, Scherr noted: "This one had it all."

PAROLE PITCH

Parole files in New Hampshire are not public record, and Flynn's lawyer, Cathy Green, declined to say what Flynn would tell the board.

Seven years ago, testifying on his motion for a reduced sentence, a tearful Flynn took full responsibility for his actions and apologized.

"I promise you I will carry this guilt and remorse with me every day for the rest of my life," he said.

Gregory Smart's father, William, told Flynn then that he might be prepared to see him go free when Flynn reached 40 but that he wasn't ready yet. William Smart has since died.

Flynn married while behind bars, has a teen stepdaughter and has earned his GED and electrician's helper license.

"This never would have happened if it wasn't for Pam Smart," said attorney Paul Maggiotto, who prosecuted Smart. "It was Smart's manipulation of Flynn that caused this crime to occur."

Flynn's age and testimony against Smart were taken into account at sentencing.

"I desperately want you to know I'm not that weak person anymore," Flynn said in 2008.

SMART'S STANCE

Smart has been at the Bedford Hills Correctional Facility for women in New York since her transfer for unspecified security reasons in March 1993. Her friend and spokeswoman, Eleanor Pam, told The Associated Press that Smart is not taking a position on Flynn's parole bid but chafes at her life sentence without the chance at freedom that the triggerman is getting.

Smart told her: "If they look at Flynn, they really should take a look at me."

Pam said that while Smart acknowledges the affair with Flynn led to the series of events leading up to her husband's death, she maintains she didn't plan it.

WHAT TO EXPECT THURSDAY

Flynn, who is serving out his sentence in Maine, will not be present at the parole board hearing. He will address the board on speakerphone. Gregg Smart's family members and friends have a right to make victim impact statements. State prosecutors will also weigh in.

The three board members are expected to confer among themselves without leaving the hearing room at the state prison in Concord and then render a decision. If parole is granted, Flynn would not be freed before his parole eligibility date of June 4 and only after his final parole plan is approved by the board.