Did Batman originally use guns and kill villains?

The answer

When Batman debuted in Detective Comics #27 in May 1939, he had no qualms about lethal force. In his very first appearance, he punched the villain Alfred Stryker into a vat of acid and remarked coolly about the death. In Batman #1 (1940), he used the Batplane's machine guns against criminals, stating, 'Much as I hate to take human life, I'm afraid this time it's necessary.' Batman's creators, Bob Kane and Bill Finger, had modeled him on pulp heroes like The Shadow, who regularly killed. The shift came after editor Whitney Ellsworth issued a directive following complaints about Batman #1's violence: 'Never have him kill again.' Batman holstered his gun permanently by mid-1940.