Pequannock High School Teacher Charged with Aggravated Sexual Assault

Wayne resident and teacher William Arnold arrested and detained after prosecutors say he sexually assaulted a 15–16-year-old student over multiple occasions; investigation ongoing.

PEQUANNOCK, N.J. — William Arnold, 53, of Wayne, a teacher at a Pequannock-area high school, was charged on September 29, 2025, with multiple sexual-offense counts after a Morris County investigation found he sexually assaulted a student on several occasions while the victim was 15 and 16 years old, county officials announced.

Arnold faces the following charges:

• Aggravated Sexual Assault (first-degree), N.J.S.A. 2C:14-2a2b;

• Sexual Assault (second-degree), N.J.S.A. 2C:14-2c3b;

• Endangering the Welfare of a Child (second-degree), N.J.S.A. 2C:24-4a1;

• Official Misconduct (second-degree), N.J.S.A. 2C:30-2a; and

• Criminal Sexual Contact (fourth-degree), N.J.S.A. 2C:14-3b.

The investigation began after the Pequannock Police Department and the Morris County Prosecutor’s Office were notified of allegedly inappropriate behavior by a school employee in September 2025. Prosecutors say the probe determined Arnold sexually assaulted the victim on multiple occasions over the prior year. Arnold, who worked at the school attended by the victim, has been suspended by the school district.

Under the Criminal Justice Reform Act, Arnold has been detained at the Morris County Correctional Facility pending future court proceedings. Prosecutors said the investigation remains active and that no further information will be released at this time.

The Morris County Prosecutor’s Office Sex Crimes/Child Endangerment Unit and the Pequannock Police Department are handling the investigation. Anyone with information is asked to call the Sex Crimes/Child Endangerment Unit at 973-285-6200.

A criminal complaint is an accusation only; the defendant is presumed innocent unless and until proven guilty beyond a reasonable doubt in a court of law.