Person of interest by Theresa Schwegel

In ten words or less: Noir tale of an undercover cop and family in Chicago.

Craig McHugh is an undercover cop who is getting too involved in his assignment. He's draining his bank account, trying to get an "in" with Asian criminals. His marriage is crumbling, and his wife is showing a little too much interest in her 17-year-old daughter's boyfriend. The daughter is picked up using Ecstasy at a party, and mom Leslie covers for her.
When Craig's former partner is killed making a drug bust, he sinks further into his secret life. But Leslie believes he is having an affair, and investigates on her own. Both Craig's wife and daughter are in danger because of his undercover activities.

Why bother? A dark and gritty tale of an undercover cop's life and the toll it takes on his family. The McHughs aren't a particularly likeable family, but the reader wonders what they might have been like years earlier. The author is an Edgar Award-winner.