Vertical coffin

Swat teams refer to doorways as "vertical coffins" because they are most vulnerable when passing through them. The new Shane Scully novel starts with a bang as an L.A. sherrifs deputy is gunned down on the front porch of a house while serving a routine warrant. The arrest is given to the Sherriff's Department by the Bureau of Alcohol, Tobacco, and Firearms, who neglects to mention the man is suspected of hording an arsenal of illegal weapons.