“Down These Mean Streets” marks its one hundredth episode with a king-sized, extra-large podcast starring four old time radio detectives. First, Alan Ladd is Dan Holiday in “Find Me, Find Death” from Box 13. Then, Dick Powell croons his way through a crime as Richard Diamond, Private Detective in “Lady in Distress” (originally aired on ABC on February 23, 1951). Howard Duff bats third as Sam Spade in “The Hot Hundred Grand Caper” (originally aired on CBS on September 19, 1948). Finally, Gerald Mohr is Philip Marlowe in “The Soft Spot” (originally aired on September 1, 1950). All that, plus find out who won our one hundredth episode contest!