There are five search patterns that can be applied in a crime scene to ensure that evidence collected is not contaminated. Strip search pattern is a technique used by two officers and the area is sectioned into north, south, east and west strips. The officers mark out the path they will use to collect the evidence and start at one point and move towards the end of the strip, if an evidence is found the officers stop and properly collects the evidence then proceeds with the same process to all the strips. Grid technique is used by officers where the scene is divided into perpendicular lanes enabling a more systematic and thorough evidence search from multiple perspectives.
Pie/wheel technique involves dividing the area into a large circle and into six parts where the officers take closer look for crucial trace evidence. Moreover, zone technique method entails partitioning the area into four equal parts and each officer is allocated one part for crucial evidence collection whereby critical trace evidence is needed to solve a case. Spiral method is used by one officer in outdoor crime scenes where the officer picks a starting and ending point and starts from the outside of the center and works towards the center so as not to destroy any piece of evidence found (de Gruijter et al., 2016).
Determinants of Search Pattern
The type of search pattern to be used is determined by various factors such as the availability of evidence collecting equipment’s, the geographical area of the scene, availability of human resources to the type of crime committed. Crimes such as burglary or rape cases will require different resources to collect evidence and package them for references. Additionally, geographical positions also determine the method used as outdoor and indoor crimes require different approaches to collect evidence. Availability of human personnel determines the method to be used as only specific personnel can search and collect evidence properly (Geberth et al., 2016).
de Gruijter, M., de Poot, C. J., & Elffers, H. (2016). The influence of new technologies on the visual attention of CSIs performing a crime scene investigation. Journal of forensic sciences, 61(1), 43-51.
Geberth, V. J. (2016). Practical homicide investigation: Tactics, procedures, and forensic techniques. CRC Pres