Ricky is Deedee's older brother and is mentioned in The Kill Order.
Biography
Ricky and his family survived the Sun Flares and lived in a village just a few miles from Mark's village. A year later, the village was attacked by the Post-Flares Coalition. Ricky's parents and younger sister Deedee were among those hit by darts containing the Flare virus. When the Flare began to spread, the villagers quickly realized Deedee was Immune to it. She was thought to be a demon of some sort and abandoned by Ricky and the rest of the survivors.
Ricky's fate is unknown but since he was not Immune, it can be assumed that he either succumbed to The Flare and eventually died or was killed by another Crank.
In the epilogue, Teresa is shown to still miss Ricky, remembering him as the loving brother he once was before being consumed by The Flare.