Juan is a student at a community college and attends a college weekend party. At the party, he meets Daisy. After making small talk, Juan and Daisy agree to go back to Daisy's house.

Upon arrival, Juan realizes that Daisy appears to still be living with her parents. He asks Daisy whether she still lives with her parents, to which Daisy truthfully replies yes. Juan assumes that Daisy is maybe a freshman or sophomore in college.

In Daisy's room, Juan and Daisy begin to engage in sexual intercourse. Shortly after beginning, Daisy's father, Vince, angrily enters Daisy's room and physically beats Juan. Afterward, Vince calls the police and Juan is arrested and charged with statutory rape. Juan didn't know that Daisy is sixteen years old.

At trial, Juan agrees to testify and states that he didn't know Daisy's age and, based on the circumstances, believed that she was a college student.

Is this a valid defense to the charge of statutory rape? Why or why not?