Indigo Slam by Robert Crais
Fifteen-year-old Teri Hewitt has been left holding the babies since her dad disappeared without trace. She wants LA private eye Elvis Cole to find him, and although he knows he should refuse and hand it over to social services, he finds himself taking on the case.
The search reveals a chronically unemployed drug addict caught up in counterfeiting scams and mixed up with the Russian mafia and Vietnamese gunmen. As the action heads towards a gunfight in Disneyland and Cole dodges his almost-girlfriend's ex-husband, he realises Teri is one whole lot of trouble he should have left to the professionals.