A mistrial was declared last night in the case of an Arlington day-care worker charged with assaulting and abusing three children after jurors said they were deadlocked on two charges against her.

The jury acquitted Heidy Terceros of assaulting a 3-year-old boy who would not take his nap, but it was unable to reach a unanimous verdict in the cases of two infant girls, who allegedly were force-fed.

Terceros, 24, did not show up for the two-day trial and was tried in absentia in Arlington Circuit Court. Prosecutors said last night that they had not decided whether to retry her on the assault and abuse charges.

"This case showed that you can get a fair trial on the evidence, even without a defendant," said Terceros's attorney, David Bernhard. He described Terceros and her mother-in-law, Teresa Villarreal, 42, as "well-intentioned day-care workers who may have overfed kids, but it didn't rise to the level of criminality."

Villarreal, who operated the day-care facility in her home on South 12th Street, has also been charged in the case. She failed to appear at an Aug. 19 hearing, and a warrant has been issued for her arrest.

Margaret Foss, one of the jurors, said members of the panel felt there was insufficient evidence in the case, which was built primarily on the testimony of a former day-care worker. Others did not believe that Terceros's actions rose to a criminal level, she said.

"We could believe that perhaps this happened," said Foss, 55. "We did not feel it [the evidence] was hard and fast. I think basically we were all happy that the place got closed down."

Jurors had an option of finding Terceros guilty of felony child abuse in the case of one of the infant girls, but they quickly dismissed that option, Foss said. After more than four hours of deliberations, one juror continued to hold out for conviction, she said.

Despite the not-guilty verdict, the parents of the 3-year-old boy said they continue to believe their son was assaulted for not taking his nap.

"We know that's what happened. He told us," said Amy Vennett, 32, a public health nurse. "He said, 'Mommy, Heidy hit me in the back hard and it hurt.' "

The verdicts came in a courtroom filled with parents of children who had been cared for in Villarreal's home. Some cried as prosecutors described abuse their children allegedly endured between July and October 1998.

The former employee, Roxano Patino, told the jury that Terceros would force-feed infants by holding them on the floor with her leg or strapping their arms at their sides in an infant car seat. She said vomit was forced back into their mouths using a rag.

Deputy Commonwealth's Attorney Theo Stamos said parents had left their children at a home that appeared safe and clean and in the care of people they trusted. She said the abuse was "low level" to keep the children in line and deceive their parents.

"When the parents were there it was a good show," Stamos told the jury. "But when they closed the door. . . . "

Bernhard argued that Patino, who had lied about her marital status, was not a credible witness. He pointed out that she had not left her employment at the home because of concerns about the way children were being treated.