Robert Sidarsky is a wealthy businessman who sexually abused both of his daughters. He molested and raped his daughters, Ellen and Susan, from the time they were 10 years old. He buys their silence by setting up substantial trust funds in their names. After his first wife dies, he remarries and has another daughter.
When the adult Susan commits suicide, Olivia Benson persuades Ellen to testify against her father by telling her that her half-sister is the same age that she and Susan were when their father abused them. The detectives arrest Robert and bring him to their interrogation room, where Ellen confronts him. He threatens to take away her trust fund, but she insists that she will send him to prison. She reads him Susan's suicide note, and bursts into tears. He is then sent to prison for the abuse. (SVU: "A Single Life")
He is portrayed by Paul Hecht.