What are the direct sources of probable cause?

1. Personal observation - the surrounding area, the environment, witnesses, and the visual impact on sight.

2. Information: Intelligence gathering in data format everything from testimonies to hardcore data either on paper or computer outputs, any reliable data is important.

3. Evidence: Any material, objects, samples left behind a scene that can trace to what had happened, and who had done it. Now we mostly use DNA and science techniques behind organics and biological samples left behind.

4. Association: one of the weaker linking system by database on known criminals and possible suspects. Not the best in probable cause, however, this method has its usefulness in linking some associates to crimes commited. (takes a criminal to know other criminals)