In the season 4 episode "Free Fall", Ryan warned her to stay away from two former prisoners after he suspected that they are targets for murder. She refused to listen got shot in the process. It is Erica who revealed to Ryan that there was a mole in the lab in a special extended scene that was available on www.cbs.com after the episode Urban Hellraisers aired.
She also helps Ryan in a case regarding abuse of eminent domain, with the government evicting people from their homes before turning the land over to a private developer (episode 505, "Death Eminent").
In a later episode, however, she puts the life of Natalia's sister at risk by mentioning on the air that she is a victim in a kidnapping (episode 508, "Darkroom").
It is implied that CSI Boa Vista was jealous of Ryan and Erica's "closeness".
She is played by Amy Laughlin.