The severed head of a Mexican investigator involved in the Falcon Reservoir case was delivered to the Mexican army today, according to state Rep. Aaron Peña, D-Edinburg. Peña reported via Twitter that he had confirmed the information with Zapata County Sheriff Sigifredo Gonzalez, whose office is heading the U.S. investigation into the Sept. 30 disappearance of David Michael Hartley. The 30-year-old McAllen man is widely believed dead after what his wife, Tiffany Young-Hartley, has described as an attack by cartel "pirates" on the Mexican side of the binational waterway.