A Wisconsin high school principal says the student was well-behaved and had good attendance. But he was no kid.

Police in Darlington say a 21-year-old man posed a 16-year-old for more than a year. Chief Jason King says police began their investigation after getting a tip. The man faces tentative charges of obstructing an officer and fraud.

Chief King says education likely was the man’s motive.

A 38-year-old woman was also arrested and is accused of posing as the supposed teen’s mom.