A Pennsylvania high school honors student is really a 23-year-old man from Ukraine with an expired visa, police said.
Samarin is accused of using the name Asher Potts to create a fake social security card and other documents, police said.
He had been enrolled at John Harris High School since the fall of 2012.
"While we do not know all of the details surrounding the arrest, we are treating this as a serious matter, Harrisburg School District Public Relations Coordinator Kirsten Keys said in a statement.
"The district will continue to cooperate fully with the police department as they move forward with their investigation," Keys said.
Samarin appeared to be hiding in plain sight. In January, he participated in a public forum addressing youth violence in the greater Harrisburg area, the station reported.
Posing as Potts, he also joined the ROTC and received several awards, including a commendation from a local congresswoman noting his installation on the National Honor Society.
Police did not say what led to Samarin's arrest.
Online court records did not list an attorney for Samarin, who is being held at the Dauphin County Jail.
Harrisburg police declined comment to INSIDE EDITION.