DAYTONA BEACH, Fla.—A former criminal justice major and college cheerleader was convicted in the killings of three Florida prostitutes more than 15 years ago. Jurors deliberated more than eight hours before returning the guilty verdict against Robert Hayes, who was linked by DNA evidence to the three victims after another killing in Palm Beach County, where he had been working as a chef until his arrest in 2019. Hayes, 39, showed no reaction as the clerk read the jury’s verdict Tuesday evening, The Daytona Beach News-Journal reported. Prosecutors will seek the death penalty during the sentencing phase beginning next week. Hayes graduated in 2006 from Bethune-Cookman University in Daytona Beach. The victims were found slain in the city his senior year. The body of Laquetta Gunther, 45, was found in a gap between an auto parts store and a mostly empty utility building around Christmas 2005. Julie Green, 34, was …