Reynaldo N. Higgins, a temporary resident of Schenectady, was charged with aggravated harassment and stalking, the Albany Times Union reported.
Police said Higgins allegedly stole the girl's contact information from a blood donor card at a high school blood drive Friday, and then repeatedly contacted her.
The girl reported the incident to school officials, the Times Union reported.
Higgins has worked for the Red Cross for four months, police said.
He was arraigned in Village Court and sent to the Albany County jail, the Times Union said.