A Southern California teacher is behind bars, accused of kidnapping three students.

John Maust, 34, had been picked up by the students Saturday, after they saw him standing on a street corner in Altadena.  

Authorities say Maust kept saying some things that made the driver uneasy and, when they tried to get out of the car, Maust allegedly pulled a knife on the students and ordered them to take him to get some fast food.  

Maust surrendered to police and is being held on $100,000 bail.