I'm asking all my friends and no one seems to know this movies name, but they remember seeing it. I'll give what i can recall. I believe this movie came out in the mid 2000s. Two murderers use a boat to navigate to lakefront houses. They either charm their way into the houses or break in. The movie takes place mostly in the living room of a house. Where the family watches each other die. Near the end the two men have a falling out and one kills the other. I believe the wife escapes to the next house over and breaks in and see's a couple murdered on the floor. The movie ends with the murderer leaving by boat and may actual end with him going to another house and introducing himself to a lady who opens the door. Pretty vague I know.