The Replacements - Bruno Johnson Series

Bruno Johnson, ex-detective with Los Angeles County Sheriff's Department and an ex-convict, is hiding out from the FBI in Costa Rica, tending bar to support eight children he illegally rescued from abusive homes. Partway through a normal day, Barbara Wicks, a former colleague and the chief of police for Montclair, California, walks into his bar. Bruno is shocked to the core.  Is she there to arrest him and take him back to California? Turns out she's there to request Bruno's help.  Two children have been kidnapped.  

The kidnapper, Jonas Mabry, was himself a victim whom Bruno rescued as a small child.  Now Mabry demands a fool's retribution, a million dollar ransom, and Bruno to put his life on the line to get the money. In this twisted turn of fate, Bruno returns as a wanted criminal to California.  Despite the risk of arrest and even his life, he cannot turn his back on these kids.  And neither can Bruno's girlfriend, Marie.  
(David Putnam)