Memory man / David Baldacci.

Enhanced descriptions from Syndetics:

This "impossible to put down" #1 New York Times bestseller introduces Amos Decker, a gifted police detective with a perfect memory who must solve a mystery he wishes he could forget: his family's murder ( Washington Post ).

Amos Decker's life changed forever--twice.

The first time was on the gridiron. A big, towering athlete, he was the only person from his hometown of Burlington ever to play in the NFL. But his career ended before it had a chance to begin. On his very first play, a violent helmet-to-helmet collision knocked him off the field forever, and left him with an improbable side effect--he can forget nothing.

The second time was at home nearly two decades later. Now a police detective, Decker returned from a stakeout one evening and entered a nightmare--his wife, young daughter, and brother-in-law had been murdered.

His family destroyed, their killer's identity as mysterious as the motive behind the crime, and unable to forget a single detail from that horrible night, Decker finds his world collapsing around him. He leaves the police force, loses his home, and winds up on the street, taking piecemeal jobs as a private investigator when he can.

But over a year later, a man turns himself in to the police and confesses to the murders. At the same time a horrific event nearly brings Burlington to its knees, and Decker is called back in to help with this investigation. Decker also seizes his chance to learn what really happened to his family that night. To uncover the stunning truth, he must use his remarkable gifts and confront the burdens that go along with them. He must endure the memories he would much rather forget. And he may have to make the ultimate sacrifice.

Memory Man will stay with you long after the turn of the final page.