Three teenage girls were charged Monday in connection with the April 21 death of 16-year-old Amy Joyner-Francis.

After a fight involving Joyner-Francis and the three accused teens in a bathroom at Howard High School in Wilmington, Delaware, Joyner-Francis fell unconscious and later died.

In a statement from the Delaware Department of Justice, all three of the accused are minors. One teen, Trinity Carr, 16, is facing a charge of criminally negligent homicide. The Department of Justice intends to try Carr as an adult. Criminally negligent homicide is punishable by up to eight years in prison.

The other two teens, Zion Snow and Chakeira Wright, have been charged with criminal conspiracy, and will be tried as juveniles. Third-degree criminal conspiracy is punishable by up to one year in prison.

The Medical Examiner determined that Joyner-Francis died from a cardiac incident related to a pre-existing heart condition; however, the cardiac incident was triggered by the assault.

According to Delaware Online, court documents indicate that the three teens planned the bathroom assault almost one day in advance. The assault was captured on video, and authorities say it appears Carr hit Joyner-Francis with a closed fist after the three girls followed Joyner-Francis into the bathroom.