Good Girl, Bad Girl by Christopher Finch
That was a tough year to be a New Yorker. The city was so broke there was a rumor going around that the mayor had been spotted on the Bowery, cleaning windshields at stoplights in the hope of scoring a nickel, or maybe a nickel bag. It's 1968, New York City is in a state of mayhem, and private eye Alex Novalis is flat broke. So he accepts a mundane missing persons gig from wealthy construction mogul Gabriel Kravitz, whose eighteen-year-old daughter, Lydia, has disappeared. The only lead is that Lydia had been sleeping with Jerry Pedrosian, a radical artist and known womanizer. But there are few clues, and everyone in Lydia's life seems to be hiding something...including her miniskirted best friend, Andrea Marshall, who Novalis is inconveniently attracted to. And as he traverses the city - from scummy artists' lofts in pre-gentrified SoHo to luxury penthouses overlooking Central Park - he'll face more danger than he signed on for. A coolly sophisticated detective story and portrait of late 1960s New York City, Good Girl, Bad Girl offers a glimpse at the forbidden sex, politics, art, drugs, and counterculture violence that ran rampant in its once gloriously gritty streets.