Essay on Triangulation and Its Utilization in Law Enforcement

Tracking and pinpointing of objects has been transformed by the invention of the Global Positioning System (GPS), commonly referred to as GPS (Anderson, ReinsmithJones & Mangels, 2011). The GPS system is utilized for navigation guidance and in militia activities such as tracking missiles and aircrafts. However, despite the numerous advantages, utilization of GPS may be a suboptimal approach in circumstances that require greater precision and accuracy since the GPS signals may be blocked by terrain or buildings. Triangulation is a substitute method that can be used to infer the position of an item by using the approximations of angles from pre-identified reference points to the object being traced. By definition, Triangulation is a method that is utilized by law enforcement officers to determine the distance and position, especially on a map, by calibrating the distance between two fixed objects and then measuring the angle from the reference points to determine the actual position of the third point (Anderson et al., 2011). In a crime scene, triangulation entails making a straight line measurement from two reference objects to the location of the evidence thus creating a triangle. The evidence is found in the angle formed by the two straight lines at a distance measured from the fixed reference points (Anderson et al., 2011).

To begin the triangulation process, law enforcement agencies should sketch evidence maps that show placement of evidence and establish the measurements to the fixed reference points. In triangulation, objects are positioned and depicted by creating a triangle that bears measurement from a single and specific identifiable point of the object to two fixed positions that are on the same level at the crime scene. Where possible, the objects are fixed to two separate triangles that are related to the opposite points on the same object. When triangulating a regular shape crime scene or items, the methods involve creating a minimum of two separate triangles of measurements. The triangles are arranged in such a manner that each originate at opposite specific identifiable points of the object and terminates at the two fixed points that are on the same plane or level. This is commonly referred to as the 2-V method of triangulation (Anderson et al., 2011). On the other hand, when law enforcement agencies are required to triangulate pliable objects, the items are fixed by creating a single triangle of measurement that originates from the Center of Mass of the object and terminates at two fixed points that are on the same plane. The detectives then measure the longest overall dimension or the pattern size of the object. In the interest of accuracy and evidence integrity, the following rules are abided by when triangulating evidence;

Triangulation should be conducted from the object without touching or moving it to the fixed reference points

The triangulation measurements must be originated from terminated on the same level. The measurements should be taken on a flat level plane.

The law enforcement agencies should not triangulate over or through other pieces of evidence

Terrestrial triangulation method is used to conjecture the position of an object using the angle approximations from reference points to the object being trailed (Advani & Weile, 2017). Despite the widespread utilization of GPS system, triangulation is gaining a significant use in the low-cost environmental monitoring and vehicular detection of pedestrians. Recently, law enforcement officers have been able to apply triangulation in robots that are engaged in collision avoidance or formation control of military navigation equipment. While both the angle and range sensors may be included in navigation systems, the angular information for triangulation is more reliable when onboard cameras are utilized. Due to this, law enforcement agencies have been able to apply iterative numerical algorithms that are based solely on angle measurements to determine the precise location of an object within a reference frame (Advani & Weile, 2017). In such instances, the algorithms rely on iteratively broadcasting the angle estimates, by observing the relative angles between robots to update the angle estimates in the global reference frame. Once the angles between these robots are known and assuming the knowledge of several reference locations, the law enforcement agencies apply standard triangulation between the robots to estimate position.

Nevertheless, the technology of triangulation is associated with two major drawbacks. To start with, before the method can be utilized, the law enforcement agencies must set up specialized equipment such as smart antenna array and triangulation towers to perform the angle estimates within the line of sight of the object; this may not always be logistically feasible (Anderson et al., 2011). Secondly, the triangulation calculations are not done in an onboard manner; as a result, the location information obtained through triangulation must also be transmitted to the tracked item. To ameliorate the shortcomings aforementioned, law enforcement agencies should use smart space vehicles and self-correcting rockets which can perform onboard computations and derive algorithms that can be entirely performed within the processor of the tracked object (Advani & Weile, 2017). Remarkably, since the triangulation system resides on the tracked object, only a limited hardware is required externally.

Additionally, Law enforcement agencies use the triangulation method to detect the exact location of gunshots this allowing police officer to get to crime scene faster than they would have if they relied on 911 calls (Anderson et al., 2011). Therefore, triangulation helps the law officers to reduce the response time. Through triangulation and utilization of acoustic gunshot detection method, police officers can achieve the following:

Increase the probability that individuals who misuse guns in urban areas are caught and punished by the law.

Decrease the incidences of gun violence. If shooters are seized before they escape, there would be a drastic decline in crime rate

Displace the gun violence from urban areas. If criminals realize that the police have a minimum response time after the gunfire, due to the utilization of triangulation method, these gangs may be forced to relocate to remote areas this reducing crime rate in notorious cities.

Moreover, the triangulation method will help police officers to save more victims since they can precisely locate the crime scene thus reducing the response time

Utilization of Triangulation in Solving McDonalds Armed Robbery at Oak Brook Village

In November 2013, law enforcement agencies at Oak Brook village were able to close a case that involved an armed robbery that that was perpetrated in a local McDonalds cafe (GIS Consortium, 2013). The evidence used to convict the culprits were obtained using triangulation and the GIS system. Following the incidence, police officers conducted a thorough investigation and associated three suspects with the robbery. To build their case and ensure a successful conviction of these offenders, the police officers used cell phone records to trace the movement of the offenders. The detectives acquired the mobile phones of the suspects and pinpointed them to the area of the robbery at the time in which it was conducted (GIS Consortium, 2013). The actual phone record was used as the key evidence in the case since the police officers were able to triangulate the precise location of the suspects phones less than a quarter a mile to crime scene shortly before and after the McDonalds shop was rooted. Remarkably, the detectives used more than just the spreadsheet with addresses and call times associating the criminals with the crime scene, they used a map and displayed the locations of the cell towers, the time of phone calls and the direction from which the calls emanated.

Using the cell phone usage reports that were given by the police detectives, the GIS staff were able to pinpoint and map the location of the cell towers that the suspects were connected to during a period before and after the crime. Consequently, the GIS officials used the azimuth sectors in respect to each call made to determine the actual direction from which the cell signal was coming from (GIS Consortium, 2013). This was depicted by the picture evidence below;

As depicted in the image, the crime scene, the McDonald shop, is located almost exactly between the two cell towers that connected the suspects cell phones. Additionally, the map generated by the GIS ascertains that the suspects indeed used their mobile phones near the McDonalds shops ate the time of robbery before and after the crime was committed. To further strengthen the evidence the police officers were able to generate the map of cell towers that the suspects cell phones connected to on their way to oak brook village as well as the cell that they connected to on their way from the village after accomplishing the robbery (GIS Consortium, 2013). These maps, the phone call records, along with other pieces of evidence that were collected at the crime scene were ultimately used as the main evidence of convicting the offenders of armed robbery. Without the triangulation of the cell phone locations and the GIS technology, the jury would have been limited to using non-graphic spreadsheets that can display the cell phone information only. Remarkably, these forms of non-graphic information are limited in that it cannot pinpoint the direction from which the calls were made.

References

Advani, M., & Weile, D. S. (2017). Position and orientation inference via on-board triangulation. Plos ONE, 12(6), 1-11. Doi:10.1371/journal.pone.0180089

Anderson, J. F., ReinsmithJones, K., & Mangels, N. J. (2011). Need for triangulated methodologies in criminal justice and criminological research: exploring legal techniques as an additional method. Criminal Justice Studies, 24(1), 83-103. Doi:10.1080/1478601x.2011.544390

GIS Consortium. (2013). Police analysis using cell tower triangulation. Retrieved from http://public.gisconsortium.org/police-analysis-using-cell-tower-triangulation/