The New Jersey teacher who is accused of sexually assaulting five 15-year-old male students was allegedly caught on video engaging in oral sex with one of the victims, according to prosecutors.

Nicole Dufault, 34, has been charged with multiple counts of aggravated sexual assault and endangering the welfare of a child, after five underage victims, all of whom are students at Columbia High School in Maplewood, NJ, claimed she sexually assaulted them. Dufault pleaded not guilty to the charges last week, but prosecutors say they are in possession of a videotape that shows her performing oral sex on one of the victims.

Legal experts—including the judge presiding over Dufault's case—say the existence of such a video could net the prosecution an easy conviction, though Dufault's attorney isn't so sure. "If the video depicts certain things happening…that doesn’t mean that my client’s not innocent,” Attorney Timothy Smith, who hasn't seen the video, told "[F]or example, she could be the victim.”

Prosecutors allege that Dufault engaged in sexual activity with the underaged teens about 12 times between 2013 and 2014, with assaults occurring on school property and in her car. Prosecutors also say that Dufault, who has two children under the age of 5, had two complaints made against her at Maplewood prior to the most recent allegations, including one complaint that she conducted "inappropriate sexual conversations in the classroom."

She is currently being held on $500,000 bail.