The murder trial begins this week for a high school teacher accused of hiring her alleged lover and two other students to kill her husband and then trying to have a key witness killed.

The three teenage boys already have pleaded guilty and are expected to be key prosecution witnesses.Pamela Smart, 23, the former media services teacher at Winnacunnet High School in Hampton, is charged with conspiracy to commit murder, being an accomplice to murder and witness tampering in the death of her husband, Gregory, 24.

The trial begins Tuesday in Rockingham County Superior Court.

She is also accused of trying to hire someone to kill a 16-year-old girl, another former student expected to testify against her. That case is to be tried later.

Pamela Smart, married for less than a year at the time of her husband's death, has denied involvement in the murder and disputed allegations one of the teens, William Flynn, was her lover.

Gregory Smart was found shot in the head in the couple's Derry condominium May 1. Police at first suspected he had surprised burglars because jewelry and other items were missing and the home appeared ransacked.

But, with the help of Ralph Welch - a cousin of Raymond Fowler, 19, a fourth teenager charged in the case - police began building their case against Pamela Smart and the teens.