Three convicted Carson City murderers will have hearings before the parole board in October.Robert Gonzales, 74, is the longest serving of the three, having spent more than 26 years in prison. Gonzales pleaded guilty to a charge of open murder with a deadly weapon in the death of his wife, Constance Marie Gonzales. She was stabbed repeatedly in the parking lot of Family Medical Center in May 1985.In February 1986, Gonzales was sentenced to life without the possibility of parole. In 2007, a judge commuted that sentence to life with the possibility of parole.Gonzales has had parole hearings in 2007 …