In any investigation there can be many lines of inquiry that can be followed, and numerous suspects who can be investigated, therefore meaning it is crucial to develop an investigation plan to assure all things go smoothly. This investigation plan will include determining which line of inquiry to follow, (which suspect) and it also will determine any resources which may be needed in order to investigate the crime effectively. This investigation pan will make sure that everyone is on the same page and working in the same direction as not to mess with the investigation. 
The OJ Simpson Case
When it concerned the OJ Simpson case, there was no investigation plan produced, causing there to be a strange order to things. Due to there being evidence of Nicole being married to OJ at her residence, the police officers immediately went to OJ's home to investigate, supposedly to make sure he was safe. From this point on the investigation plan only concerned OJ Simpson and no one else, therefore supporting the defences claims that OJ was framed due to his race, leading to OJ's acquittal.
Also when investigating the scene of the crime, the standard procedures were not followed properly, for example there was no common approach path established,therefore showing that no clear plan or procedures were ever put in place by the officers at the scene, and investigating the scene.