Myles J. Scannel, Senior Patrol Inspector, Marfa, Texas, was shot and killed on September 9, 1929, on the banks of the Rio Grande River near Polvo, Texas, southeast of Presidio. Inspector Scannel was working alone and apparently was attempting to arrest several aliens. Signs indicated that, while walking with the individuals he had in custody, Inspector Scannel was shot from ambush by someone else. Inspector Scannel's body bore two bullet and fifteen stab wounds. There is no information available concerning whether or not the killer or killers were identified and apprehended.
Inspector Scannel had entered the Service as a Mounted Watchman in September 1921 at Presidio. He was among the first Patrol Inspectors to be appointed to the Border Patrol in 1924, and became a Senior Patrol Inspector in July 1926.