The Barking Dog

A barking dog complaint is sent to the Seattle Patrol section to handle. Patrolman Samuel Jones pulls up to the house and has heard the dog barking for the last block. He knocks on the front door where the dog is currently barking out back. The front door opens a crack. A little old, gray haired lady looks up at him, “Sonny, you need to keep your dog outside. He is not getting into my house. Now be off.”
The Patrolman calls Janette Rage, a female Homicide Detective to help with the little old lady. Rage gets invited into the little old lady’s house and finds she has an empty two-story doghouse, no dog and one cat. While Rage is there, several hooded and armed men break the back door down. When Patrolman Jones arrives, he finds three armed men all dead on the floor near the back door. Rage had locked the little old lady in the bathroom before the back door gave in.
What could a two-story dog house contain that is worth getting shot for? Or is it the garage that has not been opened for ages. Maybe it is the antique car, covered in dust they want?