**2. Spatial information in Forensics: attributes and requirements**

As already noted, crime scenes, on which forensic investigations are conducted, can be initially classified into two types: those that occurs in small areas, frequently indoors, and those that take place in large areas, outdoors. Thus, location and area size determine the methods to be used, creating some limitations that make it useful or useless the instrumentation according to its technical specifications. Any case, it can be said that evidences acquire particular geometric arrangement on a three‐dimensional frame. The spatial relationships between evidences in a crime scene are described by the following basic geometric concepts: distances (measured on different planes), angles (defined both on a vertical plane and a horizontal plane), height differences (distances measured on a vertical plane) surfaces or volumes.

It is a well‐known fact that the ability to image recognition in humans is an extraordinary attribute. That is the reason because images have traditionally become the main communica‐ tion way for humans to grasp and transmit spatial relationships between objects in scenarios. Recognizing the importance of ocular inspection in police investigations, digital images constitute a lifelong testimony of an instant, through which the facts can be explained and reconstructed. Thus, images have taken a key role in criminal investigations and they are the basis for some forensic researching areas such as ballistics or calligraphic.

A crime scene is somewhat brittle over time. This is the reason because data acquisition should be performed before the evidences could be degraded, modified or disappeared. Later, when forensic analysis is in progress, it is often required coming back to the scenario. In that moment, a real and accurate 3D reconstruction is essential to reinforce stated hypothesis or establish new ones.

The main goals in forensic infographics are geometric accuracy, realism, flexibility, dynamism and completeness (**Figure 2**):


**Figure 2.** Example of the main goals in forensic infographics.

**2. Spatial information in Forensics: attributes and requirements**

height differences (distances measured on a vertical plane) surfaces or volumes.

basis for some forensic researching areas such as ballistics or calligraphic.

new ones.

and completeness (**Figure 2**):

6 Forensic Analysis - From Death to Justice

guarantee accuracy and reliability.

general and detailed information.

As already noted, crime scenes, on which forensic investigations are conducted, can be initially classified into two types: those that occurs in small areas, frequently indoors, and those that take place in large areas, outdoors. Thus, location and area size determine the methods to be used, creating some limitations that make it useful or useless the instrumentation according to its technical specifications. Any case, it can be said that evidences acquire particular geometric arrangement on a three‐dimensional frame. The spatial relationships between evidences in a crime scene are described by the following basic geometric concepts: distances (measured on different planes), angles (defined both on a vertical plane and a horizontal plane),

It is a well‐known fact that the ability to image recognition in humans is an extraordinary attribute. That is the reason because images have traditionally become the main communica‐ tion way for humans to grasp and transmit spatial relationships between objects in scenarios. Recognizing the importance of ocular inspection in police investigations, digital images constitute a lifelong testimony of an instant, through which the facts can be explained and reconstructed. Thus, images have taken a key role in criminal investigations and they are the

A crime scene is somewhat brittle over time. This is the reason because data acquisition should be performed before the evidences could be degraded, modified or disappeared. Later, when forensic analysis is in progress, it is often required coming back to the scenario. In that moment, a real and accurate 3D reconstruction is essential to reinforce stated hypothesis or establish

The main goals in forensic infographics are geometric accuracy, realism, flexibility, dynamism

**• Accuracy** in spatial positioning implies planimetric and altimetric positioning. It would be possible in 3D reconstructions, an accurate measurement of angles, distances, heights, surfaces and volumes. This implies that data acquisition methods (photography, photo‐ grammetry, terrestrial laser scanner, etc.) should ensure a reasonable uncertainty values to

**• Realism** is understood as the ability that computer graphics has to evoke and reproduce crime scenes. 3D virtual models become really important in court to verify witness testi‐ monies or to support lawyer's theories, enabling the reconstruction of facts and accidents.

**• Flexibility**. Understood as the set of graphic properties in 3D scenarios that allow us to change both the observer point of view and the scale. While traditional photography provides an image from a single point of view, the camera at the time of the shooting, the three‐dimensional graphics let us change the point of view, placing virtually the investigator in the position of any person involved in the facts. Furthermore, changes in scale provide

If these properties remain, it would be possible to give consistent and accurate answers in forensic analysis. Answers based on interactive simulations that allow elaborating more robust hypothesis about the events and to explain all their circumstances. Spatial data sets, coming from different sensors, provide a broad range of geomatic products that are necessary to describe in order to establish their properties and requirements.
