FBI Handbook of Crime Scene Forensics by Federal Bureau of Investigation Read Free Book Online

Evidence .
For known hair samples, collect at least 25 hairs from different parts of the head and/or pubic region. Comb and pull out the hairs. Submit hairs in clean paper or an envelope with sealed corners.
When possible, submit the entire garment or textile. Submit fibers in clean paper or an envelope with sealed corners.
    Image Analysis Examinations
    Image analysis examinations are conducted by the FBI’s Operational Technology Division (OTD), Digital Evidence Laboratory (DEL), Forensic Audio, Video, and Image Analysis Unit (FAVIAU).
    The OTD DEL has different acceptance criteria and a different physical address than the FBI Laboratory, as described below.
    Photographic Comparisons
    Examinations of film, negatives, digital images, photographic prints, and video recordings, including surveillance images, involve comparisons of subject(s) or object(s) depicted in questioned images with those in known images. Subject(s) or object(s) also can be compared between multiple questioned images. Subject comparisons include facial comparisons or can be made between like body parts, such as hands or ears. Examples of objects that can be compared include clothing, firearms, and vehicles.
    Photogrammetry
    Physical dimensions can be derived from images through the use of geometric formulas or on-site comparison. For on-site comparisons, examiners enter the scene and place a height chart at the location of the subject(s) or object(s) of interest. Examples of photogrammetry include determining the height of a bank robbery subject(s) and the length of the weapon(s) used by the subject(s) depicted in surveillance images.
    Authenticity and Image-Manipulation Detection
    Photographic evidence—including film, video, and digital images—can be examined to determine whether the image is the result of a composite, an alteration, or a copy.
    Location, Time, and Date
    Examinations of photographic evidence can determine the location, time, and date that an image was taken.
    Source and Age
    Photographic products, including film and prints, can be dated, and the source can be established by examining manufacturing characteristics. This can establish the time frame during which a photograph was taken.
    Cameras
    Cameras, both film and digital, seized as evidence can be compared with images to determine whether a specific camera captured a specific image. Similarly, digital video cameras can be compared with video clips.
    Video
    Still images can be produced from video clips, enhanced and enlarged, and used in courtroom presentations.
    Automobile Make and Model Indentification
    Vehicles depicted in surveillance images can be compared with the National Automotive Image File to determine make and model.
    Child Pornography Examinations
    Seized images of child pornography should be searched for known victims by checking with the National Center for Missing and Exploited Children and the Innocent Images National Initiative. The images also can be compared with images in the Child Exploitation and Obscenity Reference File to identify the source of the images. Video clips can be examined to determine if any of the people and scenes depicted in the video clips are also recorded as still images in the reference file. Video clips and still images also can be examined to determine if they depict recordings or images of real people and events or whether they represent computer-generated subjects and events.
    Questions concerning image analysis examinations should be directed to 703-985-1393. Questions concerning image analysis evidence should be directed to 703-985-1388 .
    Image analysis examinations may not be submitted directly from entities outside the FBI. State, local, or international agency cases must be submitted by the FBI field office servicing the area and must meet one of the following two criteria: 1) the state, local, or international case has a nexus to an ongoing FBI investigation or 2) the FBI division head deems that the case is of enough regional