An Oregon man posed as a high school student on Snapchat and Instagram before meeting up with two children he sexually assaulted, authorities said.

Lafayette A. Castillo, 26, was indicted Friday on charges including rape, attempted rape, sexual abuse and sodomy after detectives learned he used the social media platforms to talk with youngsters online, the Washington County Sheriff’s Office announced Sunday.

Castillo, of Beaverton, then met two victims, ages 12 and 14, in person and attacked them. Investigators had been tracking Castillo’s online presence for the past several months and believe he also targeted other children based on his social media activity, sheriff officials said.

Castillo, who was arrested Jan. 15, remained in custody early Monday in lieu of $1.5 million bail, jail records show.

Anyone with additional information about Castillo — or other potential victims — is asked to call sheriff’s officials at (503) 846-2700.