ZAPATA — A Texas border sheriff on Thursday said he was calling directly on Zeta operatives to simply produce the body of a missing U.S. citizen believed shot and killed last week by drug gangs on Falcon Lake reservoir. “All we want on this side is a body,” Zapata County Sheriff Sigifredo Gonzalez said at a news conference here attended by three congressmen and a host of other U.S. officials. Gonzalez said he had made his entreaty privately through channels he could not disclose, but that now he was making his request public so the Zetas — an assassination hit...