McALLEN, Texas -- John and Wanda Casias knew the risks of being missionaries in one of Mexico's most violent, cartel-dominated regions, their children say, but they refused to curtail their work and instead put their ministry ahead of their safety.
The couple's slaying this week during a home invasion comes as missionary groups are rethinking how they prepare their volunteers to live in Mexico and other hotspots -- or whether to send them at all.












