A Fairfax woman accused of killing her 2-year-old granddaughter by tossing her off an elevated walkway at Tysons Corner Center last year is now on trial.
Public defender Dawn Butorac has said her client suffers from significant mental illness.
Rosa has pleaded not guilty by reason of insanity to the charges.
In opening statements Monday afternoon, Butorac says Dela Rosa was on a "downward spiral of mental illness and became psychotic" in the days before she put her 2-year-old granddaughter over a sixth-story walkway railing at Tysons Corner Mall.
Prosecutors say Carmela Dela Rosa's conduct was premeditated and that she was not insane when she tossed Angelyn Ogdoc off the sixth-level walkway following a family outing.
The girl fell about 50 feet and died nine hours after the fall.
Prosecutor Ray Morrogh says that Dela Rosa knew exactly what she was doing and that it was wrong at the time of the baby's death.
“The evidence will show that she knew she was throwing a child off a bridge and she knew that child would die," Morrogh said in court.
Morrogh called her a "spiteful woman who wanted revenge. This was pre-meditated. She planned it.” Prosecution witnesses are expected to begin testimony Tuesday.
Witnesses include the victim’s mother, Kathlyn, who was present at the time when the child was thrown off the walkway.
Prosecutor Ray Morrough and Butorac focused their questions to the jury around mental illness and whether jurors could be objective when considering what factor lead up to the death. Prosecutors contend Dela Rosa threw the child off the walkway, then told a security guard she did it.
Defense attorneys claim Dela Rosa was insane at the moment it happened and can be found not guilty by reason of insanity. Butorac said Dela Rosa's long and at times debilitating history of mental illness intensified in the days leading up to the crime.