FRISCO (CBSDFW.COM) – A Frisco Kung Fu instructor will spend at least four years in prison for sexually assaulting one of his students.

On Friday a jury found Ricky Earl Anderson guilty of Sexual Assault of a Child. The group concluded Anderson sexually assaulted one of his female students at his apartment in Richardson, in 2004. The victim only recently reported the incident to police.

Collin County prosecutor Paul Anfosso explained his team didn’t have to prove that Anderson coerced the girl, who was 15 years old at the time, to have sex.

“It’s not required that we prove any kind of force when the theory of the case is that the victim is under 17 [years old],” he said.

Anfosso fears there may be other victims who haven’t come forward and said he wants to make it known to parents that Anderson has also taught Kung Fu in Fort Worth, Garland, McKinney, Richardson and Royce City.

The jury sentenced Anderson to eight years in prison and he has to serve at least half of that before becoming eligible for parole. Once released from prison the now 48-year-old will have to register as a sex offender for life.