The Midnight Taxi by Yosha Gunasekera

Siriwathi "Siri" Perera drives a taxi in New York City. One evening she picks up public defender Amaya Fernando and Siri senses they could possibly be friends, since both are Sri Lankan. While in Brooklyn, Siri then gets another fare and is stunned soon after to find the man dead with the knife still in his chest in her back seat. She then calls Amaya for help and, after calling the police, Siri is then arrested for murder. While out on bail, with Amaya's help, Siri must investigate who the man she supposedly murder was, in addition to finding the real killer to clear her name. The Midnight Taxi is a debut mystery featuring an likable main character in Siri, with a rich backstory.