Mercedes Garrison is the bride of Nick Vance and the reported sister of murder victim Christine Garrison, who’s later instead revealed to be Mercedes’ daughter.
History[]
Mercedes’ family has a colorful history. Mercedes was pregnant with Christine at age 13, so her parents and Mercedes lied to Christine and everyone else that the two were sisters to spare the family embarrassment. Mercedes was arranged to marry Nick, as the Vance's were losing their net worth and running off assets, and the Garrisons’ recently financial climbing would solve the Vance's problems and get the Garrisons a ticket to a more prestigious social life. Mercedes had a history of mental illness buried under too many psychiatric prescriptions, Christine was addicted to drugs, and Nick constantly had affairs with other women of a lower social status than his family.
It all came to a head when Christine had sex with both Nick and his brother Ethan, while she was still underage. She and Mercedes fought over being told her true parentage by Mercedes. Christine was later found killed, and it took untangling both families’ histories and problems to find out the truth. The Vance brothers were arrested on statutory rape to but time for murder charges, but Mercedes herself was a suspect and eventually tried. Still insisting on the marriage, the families conspired to have Mercedes receive an insanity verdict so she could be released in time for the wedding. The Garrisons sent their housekeeper overseas to another one of their properties to silence her testimony.
When the truth about Mercedes and Christine came out, even the Garrison parents were suspected. As the entirety of both families were prepared to blame Pepper Garrison, but argue it was self-defense, the burned-out prosecution begrudgingly dismissed all charges. The wedding proceeds, and the problems of both families are almost instantly rectified. (L&O: “Merger”)