Law & Order: SVU Season 23 Episode 19 revolves around two cases, one from years ago and one in the present.

In 2001, the cop who would eventually become Deputy Chief Garland is working a missing child case, but the case is interrupted when the cops are summoned to help deal with the 9-11 attack. In the present day, remains that appear to be of a child the missing girl's age are found in the water.

Garland hears about the discovery on the news and contacts Benson. He explains the case he was working and asks SVU to look into it. Benson assigns Rollins and Velasco to do so.

Meanwhile, a woman who meets men on a Sugar Daddy site steals a bunch of expensive watches from her date. She uses a false name but is identified via DNA. After she is arrested, Carisi tells Benson that the woman is one of Henry Messner's victims, who has been fleecing rich men ever since Henry got sent back to a psychiatric institution instead of standing trial for the rape.

Libby has never been arrested before and her DNA is not in the system, causing Benson to realize that someone used the rape kit data to identify her -- a total breach of ethics even though the process is legal.

To find out what happens, watch Law & Order: SVU Season 23 Episode 19 online.