   Gulf Cartel Rogue Mexican police suspected in killing of 3 US
citizens  MATAMOROS, Mexico Take an imperious mayor. Throw in a
rogue police unit. Find dead bodies dumped in a remote location.
It's a fatal pattern in Mexico. It happened in Iguala in
Guerrero state along the Pacific Coast, where a crooked mayor
allegedly ordered police to round up 43 student teachers in late
September. They vanished, and authorities now say the police
turned them over to gang members who killed and burned them.
Street protests over the killings have rocked Mexico. Another
case happened far more quietly here along the border with Texas.
The victims were three U.S. citizens, a woman and her two
younger brothers. A fourth man, a Mexican, was also killed. Each
was executed...