Meh... There are a lot of stalker/obsession movies out there, and this had the potential to be somewhat original! Unfortunately they missed the opportunity and fell flat.
First of all, you gave the key plot point away in the trailer. We already know this guy isn't her husband, so I was expecting there to be some other twist, but there wasn't.
Secondly, what was the importance of the creepy guy in the convertible? They made him seem super important up until "Russell" killed him and buried him in the backyard. Why put so much emphasis on his presence, his testimony, and him bringing Jennifer flowers if it was literally for no reason. I guess they tried to use him to show that "Russell" is a homicidal maniac, but they went about it the wrong way.
Thirdly, how long ago had "Russell" killed Jennifer's parents that they were already decaying in their bed? The timeline wasn't well established so you couldn't really get a sense of how long it took for events to happen. Also, no one noticed or seemed concerned about their neighbors?? The mail was piling up and I would assume that level of decay would cause a reeeeeaaaally strong odor.
Fourth, what was the significance of the detective's missing daughter, other than trying to humanize him and give him an interesting back story....btw, it did neither.
Lastly, how in the world did "Russell" think he was gonna take Jennifer home in the midst of a police investigation and the detective wouldn't look into the fact that he gave a fake address and phone number?? Not great villain work dude.
I was disappointed because, what I thought was happening, was the mystery convertible guy was the actual mastermind and "Russell" was just being used....or something. But no, he was just some random concerned citizen.
All in all, it was entertaining like a Lifetime movie, and most of the acting was decent, but it was just a poorly written story that fell short of what it could've been.