Two of three suspects pleaded not guilty to the sniper slaying of a 14-year-old girl who was shot through the heart as she rode in a school bus to a basketball game.

Scott Chipman, 24, of Dennis, and Caren Stenroos, 32, of Wareham, appeared in Plymouth District Court Friday to answer charges in the death last Saturday of Robyn Dabrowski.The New Bedford teen and another dozen girls, members of New Bedford's Technical High School girls' basketball team, were on their way to a game in Falmouth when their school bus was fired upon on Route 25 in Bourne on Cape Cod, state police said.

A third suspect, William Ferrara, 42, of Wareham, was arrested Thursday night and charged with murder in Dabrowski's death. But Ferrara was taken to Tobey Hospital in Wareham after he complained of chest pains, state police said. He remained hospitalized Friday, with a police guard outside his room. State police said it was not known when he would be arraigned.

Stenroos was arrested Thursday night in her home and charged with being an accessory after the fact of murder. Chipman, who is charged with murder, surrendered to police and was arrested just after midnight at his home.

Both pleaded not guilty at their arraignment. Chipman was denied bail, and Stenroos was ordered held on $75,000 surety, or $7,500 cash.

Robert Dabrowski leaped from his seat in the courtroom and began shouting when he saw the two defendants accused in the death of his only child, who was buried Wednesday. He had to be restrained.

"God's by our side, and you can see Robyn had a peaceful (funeral) ceremony . . . and the very next day these people were apprehended," Dabrowski, a letter carrier who is divorced from Robyn's mother, said after the hearing.

Prosecutors and police said the attack on the bus was a deliberate but "apparently random act."

Stenroos was not present during the shooting but allegedly was asked to dispose of some evidence, prosecutors said. Investigators also found ammunition at her home. Police said the fatal shot was fired from a high-powered M1 rifle, which has not been recovered.

The shooting was one of several snipings reported in southeastern Massachusetts in recent weeks, but authorities said there appeared to be no connection between Dabrowski's slaying and the other shootings.

Also aboard the bus, besides Dabrowski and a dozen other members of the freshman girls' basketball team, were the driver and the victim's mother. Jo-Ann Dabrowski had been serving as a chaperone for the team.