The Truth Seeker by Dee Henderson

Book 3 of The O'Malleys

Summary: 

Women are missing.

Amy Ireland disappeared twenty years ago without a trace. For U.S. Marshal Quinn Diamond, it's a case that has never closed. He's still searching--determined to learn the truth.

They are turning up dead.

Lisa O'Malley is a forensic pathologist; mysteries are her domain. She has worked crime scenes in Chicago for years. Examining a sea of evidence, the connections between victims are so fain that they fade into ill-defined wisps as she searches for a pattern. 

Lisa O'Malley is running out of time. 

The threads are pulling Lisa's and Quinn's cases together. And where they intersect there's a killer who will stop at nothing to see his secret remain buried. 

And now she's missing, too. . .

Quinn wanted Lisa's help. He never planned to put her in danger. She didn't expect him to invade her heart...or his God to change her life. And while Lisa understand death and darkness all too well, she's about to discover love and the Resurrection. 

Opening Lines: 

The fire had been alive; it had left its signature in the coiled, twisted wood, the bent metal, the heavy ash. It was a tamed beast, but still here, ready to come back to life with a nudge. Lisa O'Malley walked with great respect up the stairs following her brother Jack into the heart of the fire damage. The heavy boots he had insisted she wear were welcome as she realized it was glass crunching beneath her feet. Lightbulbs and picture frames had shattered in the heat.