Thomas Perry pulls the old switcheroo in A SMALL TOWN (Mysterious Press, $26). Instead of sending a single endangered innocent on a desperate race to escape some nefarious villain, he lets a group of villains loose on a defenseless town and sends a lone avenger to chase them down. Ever the master of detail, Perry first takes us to the Weldonville Federal Penitentiary in rural Colorado to marvel at the ingenuity of a dozen prisoners who escape by killing a dozen guards. But that’s not the worst of it. After dressing in the guards’ street clothes, the escapees allow more than 1,000 other prisoners to descend on the town “like an invading army” to kill and rape and burn the place to the ground. In effect, “they murdered Weldonville.” Two years later, Lt. Leah Hawkins is put on leave from the Colorado Bureau of Investigation and unofficially licensed to hunt and kill the 12 ringleaders, now scattered across the country.

Hawkins commences her crusade with Albert Weiss, who murdered a guard named Harry Costa and his family and is now holed up at his mother’s house in Naples, Fla. After polishing off Weiss, Hawkins heads to Buffalo, “the City of Good Neighbors,” to inflict her brand of vigilante justice on Viktor Panko, a master forger who murdered another guard, raped his schoolteacher wife and left her tied up for a fresh wave of escapees.

In each case, Perry is meticulous about describing the particulars of Hawkins’s tactics, from tracing one felon through his taste in ethnic food to infiltrating a white supremacist gang that another is operating in the Ozarks. In the end, any moral argument raised by the killings seems to interest this author less than the detailed planning behind them and the craftiness of the strategies used to execute them. Sorry to do this to you, old chum, but aren’t you awe-struck by the beauty of my technique?

♦

Whatever your literary tastes, a shot of Amos Walker is always bracing. A Detroit private eye of the old school, he smokes, he drinks, he uses creative language and, as he says in Loren D. Estleman’s WHEN OLD MIDNIGHT COMES ALONG (Forge/Tom Doherty, $26.99), “I’m not against getting my hands dirty, but when I do I like to know the reason.” Walker’s client, Francis Xavier Lawes (“You can call me X”), is paying him good money to determine whether his wife, who has been missing for six years, is well and truly dead, freeing X to remarry.