June 5 will mark two years since the disappearance of Lisa Stone, a 52-year-old lesbian from Dallas whom police believe met with foul play. But Stone’s friends, who became known as “The Facebook Detectives” thanks to an episode of CBS’ 48 Hours that first aired more than a year ago, still haven’t given up on solving the case. On Sunday, to mark the anniversary, a benefit concert in Stone’s honor will be held in Mesquite, where she and her friends went to high school together. The concert featuring American Idol finalist Jason Castro will benefit the national Cue Center for Missing Persons. Special guest speakers will include Stone’s friends Tina Wiley Stringer and Tammye Markle Ritter. The concert runs from 3-6 p.m. at the Rodeo City Music Hall. Tickets are $25 and can be purchased here.