Murder by Numbers (2002) on Netflix

Beyond having some of the same classes in their senior year at a San Benito, California high school, Richard Haywood and Justin Pendleton seemingly do not associate with each other, and what they know of each other do not like. Richard is wealthy, extroverted, popular, smart but an underachiever. Justin is an introverted intellectual loner. These outward appearances belie the fact that unknown to anyone that knows them, they are indeed friends, at least in their joint fascination with committing what they consider the perfect murder, which includes framing someone else for the act. Justin is largely the planner, Richard the director of executing the plan. When a young woman who is eventually identified as Olivia Lake is found murdered, Richard and then Justin eventually come into the radar of San Benito homicide detective Cassie Mayweather, the lead investigator in the case. Richard being identified as peripherally related to the case was always part of their plan to allow the pair to monitor the investigation. Richard and Justin expect the investigators to find the physical evidence they have left behind and piece together a story that they have concocted, a path which Cassie's partner, newly minted detective Sam Kennedy, seems to be following. But an issue from Cassie's past, which few if any of her colleagues know about and which is the reason behind her difficult but dogged nature, places her drive to get Justin and particularly Richard, who she is certain is the one dictating the plan, are brought to justice, despite the physical evidence not pointing in their direction. Richard and Justin's plan may be affected by their relationship with an unwitting third party, classmate Lisa Mills. Conversely, Cassie may have troubles getting the justice she wants because of her nature leading to the thought that her biases are getting in the way of seeing the evidence for what it is. The rest may be a battle of wills between Cassie and the high schoolers in who will break first.