A Delaware judge says an insurance company must extend liability coverage to a teenager who was convicted of criminally negligent homicide after a school bathroom attack captured on cellphone video that left a 16-year-old girl dead.

The judge ruled Wednesday that USAA Casualty Insurance Company must indemnify Trinity Carr under her mother's homeowner's policy, which covers claims for bodily injury.

Carr is a defendant in two lawsuits filed by the family of Amy Joyner-Francis.

An autopsy found that Joyner-Francis, who had a rare, undetected, heart condition, died of sudden cardiac death, aggravated by physical and emotional stress from the April 2016 fight at Howard High School of Technology in Wilmington. Cellphone video of the attack, which gained national attention, shows Joyner-Francis struggling to fight back and escape as she is repeatedly hit and kicked in the head while her assailant holds on to her hair.

Carr, who is now 19, was adjudicated delinquent by a Family Court judge and sentenced to six months in a juvenile facility in 2017.

Delaware's Supreme Court upheld a conspiracy verdict against Carr last year but overturned her homicide conviction, saying no reasonable fact-finder could have found that she acted with criminal negligence.

USAA argued that it had no obligation to defend or indemnify Carr under the provisions of her mother's insurance policy, which covers bodily injury and property damage claims caused by an "occurrence." The policy, which defines "occurrence" as an "accident," excludes coverage for injury or damage "which is reasonably expected or intended by any 'insured'" including injury or damage that "is of a different kind, quality or degree than initially expected or intended ..."

Judge Noel Primos ruled that the bathroom fight qualified as an "occurrence" under the policy, and that USAA had failed to show that an exclusion regarding intentional conduct applied.

"While there can be no dispute that Ms. Carr intended to harm Ms. Francis, there is no indication ... that Ms. Carr either intended to cause Ms. Francis' death or expected that her death would result from her ... actions," Primos wrote.

Primos also noted that the video of the attack, while disturbing, confirms that the harm resulting from Carr's intentional conduct "was not reasonably foreseeable."

"Indeed, this court concurs with the Supreme Court's assessment that the video does not show a 'severely violent' attack, but rather a physical altercation during which Ms. Carr rather ineffectually struck at Ms. Francis and pulled her hair, and the two ended up on the floor pushing against each other with their feet," he wrote.

At the same time, Primos acknowledged the public policy implications of the insurance dispute.

"On the one hand, there is the well-established Delaware rule that an insured 'shall not profit by way of indemnity from his own wrongdoing,'" he noted. "On the other hand, there is an innocent victim, Ms. Francis, whose heirs and family members would be negatively affected by the denial of coverage for Ms. Carr."

Prosecutors traced the bathroom assault to an online group chat the day before, when Joyner-Francis had offered advice to a friend about a problem involving a boy, telling her friend to "just be careful." Joyner-Francis warned that someone might "switch up," or betray another person. A police detective said Carr thought Joyner-Francis was talking about her as the possible traitor. A Snapchat posting that same day by one of three girls charged after the incident shows Joyner-Francis talking to Carr in the bathroom, purportedly to try to defuse the situation. The posting notes that Carr was "bouta fight her," followed by several emojis indicating that a person was laughing so hard she was crying.

Carr and Zion Snow, who was convicted of conspiracy in the attack, are named as defendants, along with the New Castle County Vocational Technical School District, in federal court lawsuits filed by relatives of Joyner-Francis.