Deputy Facing Charges After 12-Year-Old Tragically Drowns During Scuba Class

In a tragic turn of events, a Texas family’s pursuit of justice has led to an arrest following the drowning of their 12-year-old daughter. The incident has cast a spotlight on two scuba companies and the individuals responsible for her safety during a diving certification class.

William Armstrong, who previously served as an assistant chief deputy in Collin County, now faces a serious charge of felony injury to a child. On August 16, 2025, Armstrong was the certified scuba instructor responsible for overseeing young Dylan Harrison’s safety, alongside divemaster Jonathan Roussel, during what was meant to be an educational diving class. However, the class ended in tragedy when Dylan vanished during the session. Alarmingly, it took over 30 minutes for her absence to be noticed, and by the time she was found, she was unresponsive and could not be revived by emergency responders.

The Harrison family, in their pursuit of accountability, has filed a lawsuit targeting Armstrong, Roussel, and the National Association of Underwater Instructors, which provided the certifications to the instructors. The lawsuit also implicates other entities associated with the scuba class. The family had arranged for the class and purchased necessary equipment at Scubatoys, located in Carrollton, Texas. This establishment hosted an initial training session before the group, comprising eight students and the two instructors, proceeded to The Scuba Ranch for the practical portion of the class.

Both Scubatoys and The Scuba Ranch are named as defendants in the lawsuit, reflecting the family’s determination to address what they view as a collective failure in ensuring their daughter’s safety.

Central to the allegations against Armstrong is the claim that fatigue may have impaired his ability to perform his duties effectively. The lawsuit highlights that Armstrong, in addition to his responsibilities at the Collin County Sheriff’s Office, held a position as a security guard. On the day before Dylan’s fateful class, Armstrong reportedly worked a full day and then an overnight shift at his second job, leaving him with “little or no sleep in the past 24 hours” before the class commenced.

According to the lawsuit, once Armstrong and Roussel realized that Dylan had become separated from her classmates, Roussel brought the other students to shore while Armstrong searched on land. Emergency personnel were also called, and “additional divers and personnel at the Scuba Ranch” arrived to aid in the search.

However, “Armstrong and Roussel were seen leaving the area and, when they returned, they were reportedly unhelpful in guiding the search for [Dylan]. Consequently, the initial search was disorganized and inefficient, wasting valuable time.”

Local Fox affiliate KDFW reported that Armstrong resigned from his position at the Collin County Sheriff’s Office in October. Scubatoys closed its doors on Jan. 31.

Armstrong was charged with felony injury to a child on Friday. After he was booked into the Kaufman County Jail, he posted a $150,000 bond and was released. His next court date was not available.