An impostor Batman killed two muggers. Batman talked to Gordon about what was happening. The impostor struck again, this time killing some would-be liquor store robbers. The media went nuts over the Batman killings. The victims all turned out to be criminals released from custody due to technicalities. Some detective work revealed the true killer - a former policeman who was dismissed for using excessive force.
Instead of letters from the fans there's a writeup by Max A. Collins titled "The Batman/Dick Tracy Connection".