The U.S. Embassy in Mexico says two Americans have been slain outside the northern industrial city of Monterrey, an area plagued by drug violence.
It identifies them as John and Wanda Casias.
The embassy says the former Amarillo, Texas, couple's family has been notified and it is providing relatives consular services.
The embassy hasn't confirmed reports that the killing happened Tuesday. Its statement provides no other details.
Valerie Alirez in Greeley, Colo., is John Casias' eldest child.
She says he and his wife were found dead Tuesday in Santiago, Nuevo Leon, by one of her brothers.
The following statement was posted to the couple's website www.casias.org:
On Janury 31st 2012
John and Wanda graduated to be with our Lord and Saviour Jesus Christ as their lives were suddenly taken in a home invasion.
Thank you all for your prayers and your continued support for the Ministry they started 29 years ago in The Republic of Mexico. Their love for the Mexican people and the burden they had for winning souls to the Lord will always be remembered.