Martinez was found guilty on August 14, 2008 of the murder of 83-year-old Nicolas Casas and his 73-year-old wife Emilia.
Police say the victims were planning to move and had their home up for sale. They say Martinez posed as a buyer for their house, and stabbed them to death with their own steak knives.
Martinez showed no emotion Friday as he heard the judge hand down his sentence.
During the first penalty phase, the jury was deadlocked 11-to-1 in favor of the death penalty. A second jury recommended the death penalty.