Unintentionally killed Lisanne Gardner, as a child
Nikki Alamain was brought to Salem by his adopted mother Vivian Alamain, who he called Aunt Vivian. Nikki was found of Vivian and his cousin Lawrence, who he new nothing about. Nikki quickly became best friends with Bo Brady's son, Shawn D. In 1992 Nikki saw his Aunt Vivian fighting with Lisanne Gardner. Vivian was on the floor and he believes Lisanne was hurting his Aunt. Nikki pushed Lisanne, who fell and struck her head on a stone cat. Lisanne died, but Nikki never knew he killed Lisanne. Nikki wasn't prosecuted because he had not meant to kill her. Nikki learned that Carly was his mom in 1993. At first he refused to have anything to do with her, but he eventually came around. Nikki decided that he would rather have his parents together and he set out to break up Bo and Carly. In 1993 Nikki believed that his mother had died, but he was overjoyed when she returned to him. Nikki, Carly, and Lawrence all left Salem near the end of 1993.
In July 1999 Nikki returned to Salem to be with his Aunt Vivian who was pretending to be dying to get revenge on Stefano DiMera. Nikki helped her while helping himself to Kate Roberts. He fell in love with Kate, but despite becoming his lover, she wasn't ready to make a commitment to him. He left town again after she turned him down for the last time.
In August of 2011, Nicholas returned to Salem to see Carly in rehab.