Donna Marshall is a female rapist and former parole officer who raped Tommy Sullivan, Detective Dominick Carisi, Jr.'s future brother-in-law.
History
When Tommy went for his parole evaluation, Donna gave him the cup to urinate in for his drug test. She then tells him that the bathrooms are flooded and that he should go in the office. When his pants are unzipped, she pulls a gun on him and rapes him. When her boss Ralph Kessel tells her that Tommy is pressing charges against her, she conducts a home inspection and plants prescription drugs to keep him from doing so. When her DNA is found on the clothes he was wearing, she comes in with her attorney, claiming that the sex they had was consensual. It is also discovered the drugs Donna planted were from another of her parolees, named Jordan Dolphy. When the SVU detectives raid Jordan's house, they discover that she also rigs his drug tests with vinegar so he would pass them, even though he is doing drugs, and that Donna has raped Jordan as well.
At trial, when Tommy testifies that he was raped, her defense tries to discredit him and claim he is lying. Jordan was supposed to testify for the prosecution, but Donna and her boss coerce him into testifying for the defense and claiming the SVU detectives made him lie about giving Donna the drugs. Barba, however, is able to prove his drug tests were rigged, and Jordan admits to the courtroom that the parole officers own parolees like him and that Donna's boss Kessel was willing to make the drug charges go away if he testified. Donna and her attorney then try to get a plea-bargain to evidence tampering, but Barba and Benson also make her plea to the rape. This expels her from the force, places her on probation for five years, and registered as a sex offender for life. (SVU: "Parole Violations")