It's a Thriller! What happened to the first husband????

After losing her husband, Derrick, in what appears to have been a random street crime, thirtysomething Emma has built a new life with widower Tom, who is kind, and successful. Emma is finally able to feel safe again, both in her relationship with Tom and in the home they've made together on the Connecticut shore. Then one day a homicide detective shows up at Emma and Tom's door asking questions. Though Emma had been cleared of her husband's murder, it appears that law enforcement is taking another look at her and the case. Are they on the right track this time? And most importantly, will the renewed investigation ruin Emma's chances of a happy life?