BROWNSVILLE – The Cameron County district attorney is requesting a new execution date for a convicted murderer.

Ruben Gutierrez is on death row for the 1998 robbery and murder of 85-year-old Escolastica Harrison, a Brownsville teacher. He lost an appeal based on a DNA request on Wednesday.

"When identity is an issue we don't know who did it. We don't know who the perpetrator is. In this case it was proven beyond a reasonable doubt to the jury's satisfaction and the court of appeals satisfaction," said District Attorney Luis Saenz.

Saenz is asking for a June execution date.