Nicole Harper is a civil rights activist who reports the abduction and torture of her sister Sara, a documentary filmmaker, and her girlfriend Alicia Ford, a singer, after both of them didn't return home for a family supper, which Nicole originally feared was due to hate messages she was bombarded with during her activism. The case was transferred to Special Victims (the old squad of the man she was dating at the time, Assistant district attorney Dominick Carisi, Jr.), when the two women's rapes and tortures were broadcast live on the internet.
Nicole was horrified and urgently stressed on finding them both alive, and she even went to the news when she feared the police wouldn't save her sister and her girlfriend in time if they didn't dedicate more to the case. After Alicia was rescued, the two captors, Rick Anderson and Steve Lang, started a bid on Sara's murder after watching Nicole's live statement.
Nicole was horrified, but after threatening Rick's wife Molly with the death penalty for her part if Sara died, Sara was rescued in time and Lang and Rick were both arrested (SVU: "Our Words Will Not Be Heard")
Carisi is asked to officiate the wedding of his former colleague Sergeant Odafin Tutuola and Phoebe Baker, to which he agreed to perform. However, after telling Nicole about this and asking her to come to the wedding, she tells him that she thinks of marriage as an older patriarchal institution "designed to transfer ownership of the woman from the father to the husband". Carisi brings up his desire to have been married by now and the two get into an argument about their opposing views on marriage. It is implied that this fight ends their relationship. (SVU: "Wolves In Sheep's Clothing")