A Cold Case

The first time Frank Koehler shot someone dead was in 1945, when he was only 16. In and out of prison several times for this and other crimes, he managed to keep his nose fairly clean through the 1960s. But in February 1970, he shot two men dead. There was a witness, a third man Koehler wounded; but the killer disappeared and eventually the NYPD closed the case on the assumption that Koehler is dead. Nearing retirement in 1997, Andy Rosenzweig, chief of investigations for the Manhattan district attorney's office, decides to make one last effort either to catch Koehler or to find proof he's…