Months after more than 100 men were arrested in a prostitution sting last year, only a small fraction of the cases have been resolved.

Critics say it's because of a major evidence flaw in the controversial "Flush the Johns" sting carried out by the Nassau County District Attorney's Office.

Of the 104 cases, 10 of the suspects pleaded guilty, one was acquitted after a trial and six cases were dismissed. The other 87 cases are still pending.

Defense attorneys say that the reason many of the cases haven't been resolved is because there were no audio recordings of any of the alleged interactions that prompted the arrests.

"This was a major operation, a lot of resources went into it, and why they didn't audio tape it is beyond me," one attorney told News 12.

The case against one of the accused men, Nicholas Sisti, went to trial today. Sisti's attorney says investigators have not produced a recording of the phone call his client allegedly made to set up a meeting for sex.

He admits that there's a video of his client in a hotel room, but says the video is very short and does not show an agreement for sexual activity in it.

News 12 reached out to the Nassau County Police Department and District Attorney's Office, but neither would comment on the evidence in the operation. The DA's office did say that it's fighting five of the case dismissals.