When Argo walks through the doors of Baltimore-Washington International Airport, he knows it’s time to work. The 9-year-old black Labrador retriever spends most of his waking hours patrolling the ...

LINTHICUM, Md. (AP) — When Argo walks through the doors of Baltimore-Washington International Airport, he knows it’s time to work. The 9-year-old black Labrador retriever spends most of his waking ...