The type of activity police investigators engage in and material gathered 41 , depending on whetherinvestigations use the reactive or proactive method. 42 , they all go through similar stages. 

     Every investigation is different and may require a different route through the process, e.g., in some cases theidentity of the offender is known 43 and the investigation quickly enters the suspect management phase. 44 ,the identity of the offender may never be known or is discovered only after further investigation. When receiving reports, counter staff should ensure that 45 record, retain and reveal all material and pass itto the investigating officer.

     A psychologist suspected that there were subtle cues that were influencing the police questioning process in interviewing eyewitnesses, which causes misremember. She watched videotape after videotape of witness interviews, looking for these cues but she couldn’t see anything. There were so many activities in each interview—all the facial expressions, the different ways the questions were posed, the fluctuating emotions—that she couldn’t detect any patterns.

    So she came up with an idea: she made a list of a few elements she would focus on—the questioners’ tone, the facial expressions of the witness, and how close the witness and the questioner were sitting to each other. Then she removed any information that would distract her from those elements. She turned down the volume on the television, so instead of hearing words, all she could detect was the tone of the questioner’s voice. She taped a sheet of paper over the questioner’s face, so all she could see was the witnesses’ expressions. She held a tape measure to the screen to measure their distance from each other.

    And once she started studying these specific elements, patterns leapt out. She saw that witnesses who misremembered facts usually were questioned by cops who used a gentle, friendly tone. When witnesses smiled more, or sat closer to the person asking the questions, they were more likely to misremember.