A birthday party went horribly awry in Moscow early yesterday, as a cop got in an argument with his wife and then stormed a supermarket, firing at least 20 times and killing three bystanders. The cop, Denis Yevsyukov, was described by one witness as appearing drunk. Four of the six who were wounded in the rampage were hit in the head and neck, suggesting that the deranged officer of the law was shooting to kill. The Moscow police chief said that it appeared Yevsyukov, who had just turned 31, suffered a psychotic episode. "His eyes were like saucers. He was out of it, didn't remember anything that had happened and was just crying." The incident has spurred calls for more rigorous psychiatric screening of Russia's police force. Yevsyukov faces 20 years to life in prison.