Three U.S. siblings found dead in Mexico in 2014 were executed by Mexican marines and a border mayor's paramilitary security team, the country's National Human Rights Commission said Thursday. Erica Alvarado Salinas, 26, Alex Alvarado, 22, and Jose Angel Alvarado, 21, all American citizens, disappeared in 2014 while visiting their father in El Control, a small town near Matamoros, a Mexican city in the dangerous state of Tamaulipas, across the border from Brownsville, Texas. Their bodies were found sixteen days later in a field east of Matamoros. They each had been shot in the head, and the bodies were badly...