Finished reading:

ON/OFF by Colleen McCullough, 2006.
Not the usual sort of book for McCullough, so I wasn't sure what to expect. It's a suspense thriller set in Connecticut in 1965-66, concerns a serial killer. After body parts are found in a freezer of a noted research lab in Holloman, CT, Det. Carmine Delmonico, is assigned to solve these heinous multiple murders. Victims are all young 16 yr old girls who resemble each other and in how they are reared. Gruesome, terrible murders. Lots of suspects, and Delmonico becomes involved with Desdemona Dupre, who works at the institute. Plenty of suspense, red herrings, killings, family secrets, etc. I never guessed who the criminal was, and the twist at the end was a shocker to me.