Carmela Dela Rosa offered no explanation, but a police officer testified Friday that she readily admitted what she had done: "Yes I did it. I threw the baby off."

The baby was Dela Rosa's own granddaughter, 2-year-old Angelyn Ogdoc. The toddler died Nov. 30 after authorities say Dela Rosa threw her off a sixth-story walkway connecting a multideck parking garage to Tysons Corner Center, one of northern Virginia's busiest shopping malls.

At a preliminary hearing in Fairfax County Juvenile and Domestic Relations Court, patrol officer Anthony Stancampiano testified that he immediately placed Dela Rosa under arrest after she admitted throwing the toddler off the bridge. Stancampiano said Dela Rosa did not give him a reason why.

In other testimony, Angelyn's mother tearfully recounted watching as Dela Rosa inexplicably held the toddler over the ledge and released her. The woman said that nothing unusual had happened that day, but that Dela Rosa had tried to commit suicide at least twice in recent months.

Dela Rosa is charged with murder. After Friday's hearing, Judge Helen F. Leiner certified the case to a grand jury. Commonwealth's Attorney Ray Morrogh said the grand jury will meet next week, and a trial date could be set shortly thereafter.

Morrogh said Dela Rosa's admission and her choice of word "threw" were telling.

"She didn't say she tripped or stumbled," Morrogh said.

Angelyn's mother and the defendant's daughter, Mary Kathlyn Dela Rosa Ogdoc, testified she had been walking just a few steps in front of the toddler and her mother and turned around to see "my mother's hands come out under my daughter, over the railing." Ogdoc's testimony was at times barely audible through the anguished sobs.

Ogdoc ran down the six flights of stairs to her daughter, who lived for several hours after the fall. When she got to the bottom, she looked up at her mother, who watched with no expression as she rested her head on the railing.

Ogdoc said the family had gone to the mall to eat at the food court and that nothing unusual happened. Under cross-examination, Ogdoc said she usually tried to keep a close eye on Angelyn when she was with Dela Rosa because of the grandmother's suicide attempts.

After Friday's hearing, public defender Dawn Butorac said Dela Rosa's mental problems were well known within the family and that she had been seeing a psychologist for 10 years. Butorac said she believes at this stage that Dela Rosa's mental health problems rise to the level of legal insanity.

While Ogdoc wept throughout her testimony and was barely able to spit out the words "my mother" without flashing anger, Dela Rosa sat through the hearing in a green prison jumpsuit, paying close attention but betraying no emotion.