Methods of Execution

In the fifth Matt Riordan novel, a well-written, well-constructed legal mystery, Huebner ( Picture Postcard ) sets his Seattle lawyer on a cold trail of evidence littered with betrayals of both private lives and professional principles. Riordan's old lover, Liz Kleinfeldt, asks him to help her get a stay of execution for Robert Polhaus, the so-called Motel Room Killer. Something about Polhaus's conviction for a series of rapes and murders smells wrong to Liz, even though the murders stopped after he was caught. Raking over the case history, Riordan discovers that the victims were connected to the same escort service; further evidence, suggesting that some powerful and protected people might have wanted these women dead, leads to another killing. Riordan's investigation builds up complex currents of suspense as each of the major characters in this tale, which focuses on the past, plumbs his or her own troubled personal history. Surprising twists in the story lead to a payoff that, while holding up to scrutiny, nevertheless seems a little weak, especially following the deft characterization and plotting that led up to it. (Apr.)