In recent times, science has provided substantial aid to crime detection. Because anything in the physical universe has the potential of becoming an item of evidence in an investigation, a wide variety of procedures may be used in analyzing and interpreting evidence in a criminal case. These procedures include handwriting analysis, forensic photography, crime scene documentation, metallurgical investigations, chain of custody, entomology, and blood spatters. The first thing you do after securing a crime scene is document it. Always take pictures. They are the best records available. They show the crime scene as it was found; where objects are in relation to other objects, victims, rooms, etc. Take notes. Describe the scene, it's over all conditions. Describe rooms, lights, shades, locks, food; anything that can indicate a time frame, condition of scene or that might have even the slightest evidentiary significance. Check dates on mail and newspapers. Diagram the crime scene. Take measurements. Photos are good to show where an object is in relation to another object, but measurements tell exactly how far. True handwriting analysis involves painstaking examination of the design, shape and structure of handwriting to determine authorship of a given handwriting sample. The basic principle underlying handwriting analysis is that no two people write the exact same thing the exact same way. Every person develops unique peculiarities and characteristics in their handwriting. Handwriting analysis looks at letter formations, connecting strokes between the letters, upstrokes, retraces, down strokes, spacing, baseline, curves, size, distortions, hesitations and a number of other characteristics of handwriting. By examining these details and variations in a questioned sample and comparing them to a sample of known authorship, a determination can be made as the whether or not the authorship is genuine.