Fidelity by Thomas Perry

Emily Kramer knows immediately that something is wrong when she wakes up one morning and her husband, Phil, is not asleep next to her. Her worst fears are confirmed when the police tell her that he's been murdered. To make the situation even more distressing, Emily discovers that Phil has drained both the couple's personal funds and his private detective agency's accounts. Emily realizes that she must try and keep the agency open with help from Phil's employees, especially Ray Hall. Emily finds the going hard at first because it seems that Phil was keeping secrets from everyone close to him. Ray, though, tries to aid her in finding out why Phil was killed. What neither of them know is that the same man who murdered Phil has been hired to silence Emily, too. Killer-for-hire Jerry Hobart is on Emily's trail, but is there some way that she can outwit him to stay alive? Fidelity reminded me of the novels of Harlan Coben and Lee Child.