Cassidy returns on Law & Order: SVU Season 19 Episode 13. He is due to testify in court, but quickly loses his temper and his subsequent tantrum causes the judge to declare a mistrial.

SVU goes to the families of several young boys who were molested by the defendant, Dr. West, but the parents don't want to put their kids through testifying at a second trial. Soon after, Cassidy gets very drunk while at a bar and Benson is called in to calm him down. She fails to do so but tells the bartender to get him home. Late that night or early the next morning, Benson is awakened by Cassidy banging on her door. He is all bloody and needs help. West has been murdered and he is the top suspect.

Benson agrees to hide Cassidy and investigate to try to prove he is innocent, but the homicide detective doesn't want SVU near the case. Benson has her team investigate anyway. Rollins finds out about Cassidy and is not happy.

Later, Stone yells at Benson for investigating this case without permission and Rollins goes over to Benson's and tells Cassidy to turn himself in before Benson tanks her career for him. They argue but Cassidy shows up to turn himself in just in time, as Holiday has evidence of his guilt and no one knows where he is.

Holiday questions Cassidy and accuses him of hating black people. She doesn't appreciate Benson insisting on his right to an attorney being respected.

Benson tells Stone the truth and he is not happy.

Later, another suspect is found and Cassidy is exonerated. He makes a confession to Stone and then tells Benson he is the love of her life.

To find out what happens, watch Law & Order: SVU Season 19 Episode 13 online.