Jonathan Aguiluz charged in death of 7-month old sister

A 14-year-old accused of killing his baby sister has been charged with first degree murder and is being held without bond.

Jonathan Aguiluz told police that he beat his sister repeatedly and then covered the mouth and nose of the 7-month-old baby girl until she stopped crying. The cause of death is{ }asphyxia, authorities said Monday.

In court Monday, it was revealed that some of the injuries to the baby were in fact post-mortem insect bites.

Montgomery County State's Attorney John McCarthy said, "This particular apartment was infested with bugs. The bugs attacked this child after she died."

Investigators say Thursday night around 10:30, Gloria Yanes, 39,{ }left for work, leaving Aguiluz to babysit 7-month-old Larissa Yanes and his 3-year-old sister overnight. When the mother got home at{ }5:30 the next morning,{ }she found the infant in a car seat in the apartment, unresponsive.

“He admitted to causing those injuries and also placing his hands over her mouth and nose as she was crying,” explained Captain Paul Starks of the Montgomery County Police.

Starks said in Maryland, it's permissible to have a 14-year-old watch a younger sibling under normal circumstances.

Sources say Aguiluz told police he was frustrated that the baby wouldn't stop crying. Neighbors call it a tough case all around.

“She never even had a chance at life...really a shame...and now it's really two lives taken away.... the 14-year-old just lost his life too,” said neighbor Brian McCoy.

Neighbor Jennifer Eguizabel added, "At 14 he should be responsible enough to know right from wrong, but it's hard because his mother had to go to work to make money for the family.

In fact, ABC7 has learned social services workers are now investigating the living conditions in the apartment,as well as suggestions that Aguiluz may have been a victim of abuse.

It is possible the charges against him could be amended, bringing Aguiluz into the juvenile system.

McCarthy added, "What's going to govern this case and where we're going to go is going to be the facts..."