A horse trainer and riding coach has been charged with sexually assaulting a teenage victim and possessing child sexual abuse materials, ammunition and drugs, the Morris County prosecutor said.

Authorities said police were notified in March 2026 of allegedly inappropriate behavior involving Troy Roberto, 55, an equestrian trainer from Hewitt and a victim who was 16 years old at the time.

Police determined that on multiple occasions beginning in December 2025 in Mendham Township, Roberto allegedly sexually assaulted the victim. Investigators also said Roberto sent and received sexually explicit photographs to and from the victim.

Roberto was arrested in Atlantic County on March 10, 2026. Authorities said he was found in possession of six Alprazolam pills without a valid prescription at the time of his arrest.

A search warrant executed on Roberto’s vehicle led to the discovery of 36 rounds of ammunition, officials said.

Roberto was transported to the Morris County Correctional Facility, where he remains detained pending a court appearance.

Roberto was charged with three counts of sexual assault, one count of endangering the welfare of a child, one count of endangering the welfare of a child — possession of child sexual abuse materials, one count of possession of a controlled dangerous substance, and one count of certain persons not to possess ammunition.