Full Disclosure by Dee Henderson

Stand alone

Summary: 

Ann Silver is a cop's cop. As the Midwest Homicide Investigator, she is called in to help local law enforcement on the worst of cases, looking for answers to murder. Hers is one of the region's most trusted investigative positions.

Paul Falcon is the FBI's top murder cop in the Midwest. If the victim carried a federal badge or had a security clearance, odds are good Paul and his team see the case file or work the murder.
Their lives intersect when Ann arrives to pass a case off her desk and onto his. A car wreck and a suspicious death offer a lead on a hired shooter he is tracking. Paul isn't expecting to meet someone, the kind that goes on the personal side of the ledger, but Ann Silver has his attention.

The better he gets to know her, the more Paul realizes her job barely scratches the surface of who she is. She knows spies and soldiers and U.S. Marshals, and has written books about them. She is friends with the former Vice President. People with good reason to be cautious about who they let into their lives deeply trust her. Paul wonders just what secrets Ann is keeping, until she shows him the John Doe Killer case file, and he starts to realize just who this lady he is falling in love with really is...

Opening Lines: 

"I'm pulling into the scene now. There are four dead, but Jackie wasn't hurt. I'll be back in touch, Dad, as soon as I know more." FBI Special Agent Paul Falcon parked behind a Chicago squad car within sight of the blue-and-white restaurant awning with Falcons scrolling across the fabric. He shoved the phone back in his pocket. It was just after eleven p.m. and the dark street was bathed in the flashing lights of squad cars. FBI Agent Sam Truebone met him as he cut between the medical examiner's van and the crime-scene van.