People lie. The challenge for Law Enforcement is to discover the truth, and when people are lying and why they are lying. Unfortunately it is very difficult to ascertain when somebody is lying, unless you have solid evidence that refutes the lie.
Expert criminals, know they have to lie, and try very hard to not leave any evidence regarding the crime for Law Enforcement to discover.
The only Person of Interest that the TPS has not interviewed is the Night Walker, and I believe he is the key to this case.
As long as he is not identified, located and interviewed chances are nobody will be charged with any crime.
Is it too late for the TPS to start a world-wide manhunt?