would shoot if they did not give him money. On May 16, five armed men boarded and robbed another boat also on the American side of the lake. There has been at least three other confirmed incidents in which armed men dressed in black have boarded American boats while they were fishing just inside of Mexican waters. In late May, a Border Patrol boat chased another boat occupied by men in ski masks but the vessel was faster than the Americans and got away. Fishermen have also reported sighting small boats loaded with Mexicans and machine guns. The pirates speak Spanish and claim to be Mexican Police officers though they have been identified by tattoos of the letter "Z" for Zeta on their arms or necks. Texas Department of Public Safety officials issued a warning for American citizens to stay on the United States side of the water and to be on the lookout for vessels used by Mexican fishermen, boats with a large prow, a small outboard motor without a cowling and no identification numbers on the hull. The warning has prevented many Texas fisherman and tourists from using the lake entirely. August On August 31, United States authorities released a statement saying that pirates aboard a small boat tried to intercept an American fishing boat but the operator outran the attackers and returned to the Texas side of the reservoir. On the side of the pirate boat was the misspelled words "Game Warden", written with tape. The fisherman noticed this mistake and assumed the approaching vessel to be a pirate. September On September 30, 2010, the most serious incident involving the pirates thus far occurred when McAllen, Texas resident and Colorado native David Hartley went missing while riding through the Mexican side of the lake on a jet ski with his wife Tiffany Hartley. According to Tiffany's report to the Texas police, men in two small boats approached and fired on her and her husband with automatic weapons in an attempt to steal their jet skis. They then chased her back to the American side of the lake. Hartley also said that her husband was shot in the head and the pirates retrieved his body and the jet ski. Mr. Hartley's body remains missing. Both the Mexican and the United States governments launched an investigation in early October. Search and rescue teams searched the lake but no evidence