KAUFMAN COUNTY, a former Texas deputy has been charged following the drowning death of a 12-year-old girl during a scuba diving certification class, authorities said.
An arrest was made after a Texas family filed a lawsuit against two scuba companies in connection with the death of their daughter.
William Armstrong, a former assistant chief deputy with the Collin County Sheriff’s Office, has been charged with felony injury to a child. Armstrong was the certified scuba instructor responsible for supervising 12-year-old Dylan Harrison during a diving certification class on August 16, 2025. He was overseeing the class alongside certified divemaster Jonathan Roussel.
According to investigators, Dylan disappeared at some point during the class. More than 30 minutes after instructors realized she was missing, she was found unresponsive. Emergency medical personnel pronounced her dead at the scene.
As previously reported, Dylan’s family filed a lawsuit against Armstrong, Roussel, the National Association of Underwater Instructors that issued their certifications, and other organizations connected to the scuba class. The family booked the class and purchased equipment through Scubatoys in Carrollton, Texas, which also hosted an introductory session before eight students and two instructors traveled to a lake at The Scuba Ranch.
Scubatoys and The Scuba Ranch were also named as defendants in the lawsuit.
The lawsuit stated that Armstrong, in addition to his full-time role at the Collin County Sheriff’s Office, also worked as a security guard. According to the filing, Armstrong worked a full daytime shift and a full overnight shift at his second job the day before Dylan’s class, leaving him with little or no sleep in the previous 24 hours.
Court documents allege that once Armstrong and Roussel realized Dylan had become separated from the group, Roussel escorted the remaining students back to shore while Armstrong searched on land. Emergency responders were called, and additional divers and personnel at The Scuba Ranch assisted in the search.
However, the lawsuit claims Armstrong and Roussel left the area for a period of time and, upon returning, were reportedly unhelpful in directing search efforts. As a result, the initial search was described as disorganized and inefficient, wasting critical time.
Local outlet KDFW reported that Armstrong resigned from the Collin County Sheriff’s Office in October. Scubatoys permanently closed on January 31.
Armstrong was charged Friday with felony injury to a child. After being booked into the Kaufman County Jail, he posted a $150,000 bond and was released. His next court date has not yet been announced.
