From St. Martin's Paperbacks: Death, Taxes, and Peach Sangria by Diane Kelly.
About the book, from the publisher:
When it comes to exposing tax fraud, Tara and her partner Eddie are really cleaning up. From their brilliant takedown of the disappearing “Tax Wizard” to their perfectly planned downfall of the “Deduction Diva,” they’ve earned the respect of their peers at Criminal Investigations. Now Tara’s ready to celebrate with an ice-cold pitcher of peach sangria—even if her next case is totally the pits…Visit Diane Kelly's website.
Tara’s looking forward to a challenge but, back at the office, everyone’s looking for love. Her boss Lu “The Lobo” Lobozinski and office virgin Josh Schmidt are signing up for an online dating service, and—to Tara’s dismay—so is her crush, Special Agent Nick Pratt. Tara’s trying to act chill. But when she learns that her next case involves cash-funneling to terrorists, it’s not just her love life that’s on the rocks. It’s her life, period.