Under Surveillance (2006)

After ten years, Justin Besler has moved back with his father. But his father's house isn't as Justin remembered. It's been renovated to support three apartments, housing somewhat shady neighbors. So when the victim of a cult killing turns up on his property, Justin grows increasingly suspicious of his new housemates. That's when Rick, a questionable friend, talks Justin into using pinhole surveillance cameras on the apartment residents. But the deeper Justin and his friends dig, the more they put their own lives in danger.