Brevard teen accused of killing toddler sister

BREVARD COUNTY, Fla. — A Brevard County teenager was charged with second-degree murder in connection with his younger sister’s death.

Noah Walls, 15, hit his 21-month-old sister, Riley Martin, Sunday at their home near Cocoa, causing Martin to fall, deputies said.

Martin was pronounced dead at the hospital.

Walls told investigators that he grew frustrated with something his sister was doing before striking her.

"Once the incident occurred, the defendant in this case actually went and got his mom and said something's wrong with the baby," said Maj. Tod Goodyear of the Brevard County Sheriff’s Office. "And she came out, and that's when we were called."

Deputies said Walls and another sibling regularly cared for Martin, but both parents were home when the incident happened.

"When it comes to that point when you're frustrated, walk away," Goodyear said. "The frustration will go away. Then come back and deal with it."

Deputies said the teen seemed remorseful when they spoke to him after the incident.

An autopsy report later found the child died as a result of blunt-force trauma.

The Department of Children and Families is also involved in the investigation.

Walls was taken into custody Monday after a court order was issued for his arrest.

He's being held without bond at a juvenile detention center.

Prosecutors are still trying to decide if Walls will be tried as an adult.