Fall from Grace by Alan Feldberg

How many bad decisions does it take to go from a conventional life to one where murder makes perfect sense? Not as many as you'd think . . .
Adrian Smythe is employed, married, and a doting father to Lydia. But he feels confined and thinks his life lacks purpose.
In an act of quiet rebellion, Adrian quits his job. He hides this decision from his wife, fearing her judgment, until finally revealing it weeks later. Appalled by his behavior, she exposes him as a fraud and a failure to their daughter.
Infuriated that his wife tarnished the thing most precious to him, Adrian goes on a rampage before leaving the family home. He moves into a small flat by the seaside, while his wife moves to France with their daughter.
Now, disconnected from everything in his past, he is finally free of the constraints he resented so much. But Adrian's new life may not be exactly what he bargained for. In fact, it could be his undoing . . .