Tuesday, he looked down on the body of a Mexican girl who’d been clubbed to death with a spade . . .Thursday, he took the examination for lieutenant and had a lot of trouble with it . . .Friday, his aunt died and left him more money than he bothered to count . . .Then Joe Burke, a sergeant out of Central Homicide, Los Angeles, turned in his badge. He bought a house, a car, good liquor, and even went in for amateur theater - just in time for a bloody off-stage killing. Joe found himself back on the homicide detail, unofficially this time, in a case that was to teach him more about ruthless murder - and about women - than he had learned in a dozen years on the force.