WHITE OAK, Md. (WUSA) -- New details about the death of an infant girl, allegedly killed by her 14-year-old brother, were revealed in the teen's first court appearance in Montgomery County on Monday.

On Feb. 8, Jonathan Aguiluc told policehe beat the infant and then covered her mouth and nose to stop her from crying. The teen was taking care of 7-month-oldLarissa Yanes and his 3-year-old sisterwhile his mother, Gloria Yanes, worked her overnight shift.

On Monday, authorities confirmed that the cause of death is asphyxia. It was also revealed that some of the injuries to the baby were insect bites.

"Anadditionally sad aspect of this is that this particular apartment was infested with bugs and the bugs attacked this child after she died," Montgomery County State's Attorney John McCarthy said.

The court ordered Aguiluc to be placed in ajuvenilefacility while the courts determine whether to prosecute him as an adult in a follow up hearing on Feb. 22.

Aguiluc has been charged with first degree murder and is being held without bond.

His mother has not been charged. In Maryland, anyone 13 years of age or older can look after a younger child.

Read or Share this story: http://on.wusa9.com/1lFs4Rj