Tuckwell and the other student, 19, an acquaintance, met during Lawn Party weekend - two days of outdoor concerts at the Ivy League school - on Sept. 16, then went to a dormitory, where the younger student fell asleep after drinking alcohol, Sutter said.
Tuckwell is accused of then using his cellphone camera to take sexually explicit photos of the student without his consent.
The younger student awoke at one point and saw Tuckwell photographing him, police said.
Police said that there was no indication the photos were distributed and that an investigation was continuing into an allegation of sexual assault. Police declined to release any other details about the investigation.
Tuckwell's Princeton-based lawyer, Arnold Mellk, declined to comment Monday.
The invasion-of-privacy charge carries a penalty of up to five years in prison, police said.
Princeton University officials did not immediately comment on the arrest.
The mix of electronic media and sex crimes was an issue in two New Jersey campus crimes in 2010. Both were at Rutgers University.
In one, student Minjin Oh pleaded guilty to making unwanted sexual contact with his sleeping roommate and capturing video of what happened on his cellphone.
In the other, student Dharun Ravi was convicted this year of invasion of privacy and bias intimidation for using a webcam to view his roommate kissing another man. The case became widely known because the roommate, Tyler Clementi, killed himself days after he learned that he had been recorded.