Creating a set of guidelines on conducting the preliminary investigation for a criminal case is extremely important as it gives a baseline for officers to follow to help prevent errors in the investigation. According to Hess and Orthmann (2010), "The initial response is crucial to the success of an investigation. Although it is popularly believed that cases are won or lost in court, more cases actually are lost during the first hour of an investigation than in court" (p. 14). After containing the incident, officers upon arrive will begin examining the scene by taking photographs, sketches or videos. After the scene has been recorded visually, officers will search for evidence, and then collect it for examination and processing while documenting what has been found during the search for clues. The victims, suspects and any witnesses will be questioned. Officers will conduct neighborhood canvasses to locate any witnesses that may not have been on the scene. All information provided by witnesses and observed by officers will also be noted and recorded.
A strategy that criminal investigators should take in order to conduct an efficient follow-up investigation is to ensure all observations and notes are shared from the officers that conducted the preliminary investigation to the officers that are conducting the follow-up. This could eliminate potential time wasting activities that had already been addressed by the first officers on the scene. Using paperwork that is consistent can allow for easier communication for these two separate investigations in case there are other officers working the case. This paperwork would let the follow-up investigators know what steps were followed during the preliminary, and if they had not been completed, why they were not completed. For instance, bad weather during the night in a rural area without streetlights may have been a reason why the scene of a crime was not thoroughly checked for evidence, but it is possible that some evidence could still be collected during a different time of the day, such as a bullet casing or a weapon tossed from a car.