OMAHA, Neb. -- New charges were filed Wednesday in the case of a former Lincoln teacher accused of assaulting teenage boys.

Sanford Kaplan was charged with eight counts of child abuse, two counts of first-degree false imprisonment and four counts of third-degree sexual assault.

Kaplan pleaded not guilty to all charges.

Investigatiors said he bound, gagged and blind-folded several teens in his home for his own sexual gratification.

The alleged assaults took place during the last eight years, investigators said.

Kaplan's trial will take place in October.