Diandra Janae Samuels (Prince William County Police)

A woman accused of fatally stabbing a Woodbridge High School football player pleaded guilty just before her murder trial was set to begin in Prince William County.

Diandra Samuels, 20, pleaded guilty to second-degree murder and robbery in the killing of Kenny Diaz, 18. Samuels, who would have faced a first-degree murder charge if the case went to trial, will be sentenced in May.

In earlier court testimony, witnesses said that Samuels and a large group of neighbors — so many that they traveled in three cars to the wooded spot where they beat Diaz — assaulted the teenager after he and three friends tried to rob a friend of Samuels’s.

Diaz and his friends were retaliating for an earlier robbery in which Samuels stole money from a friend of Diaz’s when Diaz and the other teen went to Samuels’s apartment to buy marijuana from her, the witnesses said.

The large group of neighbors from Samuels’s apartment complex beat Diaz in the woods on Sept. 21. Samuels then stabbed him, according to earlier court testimony.

Samuels was charged with murder, and 11 others, four of them juveniles, faced lesser charges including abduction and assault by mob.

Of the adults charged in the case, two have pleaded guilty and five are scheduled to be tried over the next four months.

Barry Zweig, Samuels’s attorney, said that Samuels expressed sorrow for Diaz’s death when she pleaded guilty Tuesday. “She’s remorseful about her actions. She’s remorseful for what happened to Kenny Diaz. She’s remorseful for putting his family in that situation,” Zweig said.