"Authority" is one of those 'Law and Order: Special Victims Unit' episodes, and episodes even in general, that a lot of people are going to remember for a long time. Speaking from experience. There are a lot of 'Special Victims Unit' episodes that have a once seen, never forgotten quality to them, and on first watch "Authority" stayed in my head for a very long time. While there are people that had reservations about it, there is one positive aspect that is pretty much universally agreed on within the fandom.
On my recent rewatch of "Authority" and of Season 9, its staying power is unlike any other episode from the season. On the whole, it is an excellent outing and one of only three episodes rated in the 9s from Season 9 to be that good. "Savant" and "Undercover", the season's two standouts, are the others. "Authority" is one of the best of Season 9, in the top 5, and up to a certain point was actually this close to being the best episode of this uneven season, complete with one of the show's best ever guest performances and being one of the season's creepiest episodes.
My only issue, and it is sadly a big one and raised my rating from a 10 to a 9, is the ending. To me, it was a silly and abrupt cop out and actually would have fared a lot better if it ended on an ambiguous trial verdict note (a la "Doubt"). Rather than the silly one that was crying out for the episode to be a two parter.
There are so many fantastic things that more than compensate though. The best aspect being the magnificent universally acclaimed performance of Robin Williams, considered one of the show's best ever guest stars for very good reason, showing expertly that he could do drama as equally well as comedy proven already in many previous roles. It is not his first creepy role, but this is Williams at his most terrifying in particularly the courtroom and the climax.
Williams is not the only thing about "Authority" that works so well. The script is taut and intelligent, especially in the courtroom. The story is intricate, intriguing and also very suspenseful in some parts. Williams' character is fascinating, one of the most fascinating and memorable supporting characters of Season 9. The regular performances are typically excellent, primarily Christopher Meloni in the climax.
Production values in "Authority" are solid and the intimacy of the photography doesn't get static or too filmed play-like. The music when used is not too over-emphatic and has a melancholic edge that is quite haunting. The direction is sympathetic enough while also taut.
Excellent episode and one of the best of Season 9. Was very close to being a show high point until it petered out at the end, which was frustrating. 9/10.