Why Is Math Important in Criminal Investigations?

Timelines

• A fundamental tool of criminal investigation is the construction of a timeline. If a safe was opened at 3:15 a.m., and a suspect was seen at 2:30 a.m. several miles away and seen again at 4:30 a.m. in the next town, investigators need to fit the actions into a timeline. The investigators need to calculate how long it would take to break into the store and open the safe, in addition to the transportation time. The calculations are all mathematical, and a timeline can make or break a case against a suspect.

Physical Evidence

• Blood spatters in accordance with mathematical rules. Bullets fly along trajectories described by math. The pattern of a wound contains information about the amount of force, the angle and the type of weapon, such as club, axe or hammer. All of these clues need to be measured and analyzed using a mathematical model. The mathematical model will yield information about the characteristics of the crime: from the distance from which a gun was shot to the likely height and strength of a knife-wielding criminal.

Toxicology

• Death leaves a chemical signature. The body reacts differently to various types of death. Investigators can narrow down the cause of death by sampling tissues from the body. The tissue analysis determines the levels of various chemicals, which vary with the time elapsed after death. The measurements and the models they fit all depend upon mathematics.

Visual Evidence

• In today's world, video cameras are nearly always present. When a crime is committed, there's often a chance that someone involved has been captured on video somewhere. The field of view of the cameras, the angles from which they shoot, the rates at which they acquire images can all be mathematically integrated to reconstruct elements of a crime. Although television shows exaggerate what can be done to sharpen video images, some sharpening is possible. Again, the procedure involves mathematical processes.