Digital/Multimedia

August 30, 2020

Digital/Multimedia (DM) Evidence - The analysis of evidence stored or transmitted in binary form.

  • Computer Forensics involves the acquisition and analysis of computer evidence such as computers, laptops, gaming systems, USB devices, CDs/DVDs, memory cards, etc. 
  • Mobile Device Forensics involves the extraction and analysis of mobile device evidence such as cell phones, tablets, PDAs, GPS devices, smart watches, etc. 
  • Vehicle Forensics involves the extraction and analysis of supported infotainment/telematics systems from vehicles. 
  • Video/Audio Analysis involves the examination, comparison, and/or evaluation of audio and/or video/audio evidence in either analog or digital format.

Computer and Mobile Forensics
Computer/Mobile forensics involves the recovery, preservation, and examination of data from computers, cell phones, and various types of digital media for use in investigations or other legal proceedings. Digital evidence can potentially contain evidence related to various offense types, such as child pornography, fraud, cyber-stalking, murder, and sexual assault.

ATTENTION – When digital evidence is collected at a crime scene, the officers or laboratory personnel collecting the evidence should have a general understanding of the possibilities of alteration or destruction.  For information regarding the collection/handling of evidence, and other considerations in this discipline, please refer to the Laboratory Customer Handbook (excerpt from Crime Laboratory Division Manual) (PDF) for specific instructions.

All submissions for Digital/Multimedia examination MUST be accompanied by the proper documentation BEFORE any examination can begin. A proper Search Warrant (which authorizes not only the seizure of, but also the forensic examination of submitted digital evidence) or Consent to Search form must be submitted along with the evidence.

  • Template for Computer Search, Seizure and Analysis Warrant (Appendix 12)

Vehicle Forensics
Vehicle Forensics is the extraction and analysis of supported infotainment/telematics systems from vehicles. Data such as the following may be recorded, depending on the type of system: 

  • Bluetooth and WiFi connected devices identified by unique identifiers.
  • Contacts, Call Logs, SMS Messages, Media Files from connected devices.
  • Vehicle Events such as doors opening and closing, gear shifts, odometer readings, in-car call logs, GPS warnings, voice recordings, hard braking, hard acceleration, traction events, driver distraction alerts, Carplay enabled, Android Auto enabled, web browser history, seat belt alerts, navigation, and more.
  • Navigation information including tracklogs which can show the trackpoints (GPS coordinates) a vehicle traveled. This differs from user-entered location information such as an entered address as it tracks where the vehicle actually traveled. User-entered location data is also often recorded. 

 

Video / Audio Analysis
Data recovered from either analog or digital multimedia format including, but not limited to, analog media, law enforcement in-car cameras, surveillance cameras, and/or magnetic and optical media can be further enhanced to provide information and/or clarification of image, audio or video to isolate regions of interest from the media.  At the current time, the laboratory does not perform audio/video comparisons or authentications (visual identifications or voice matches)   Audio enhancement can be performed to attempt to remove undesirable noise from a particular frequency, such as an electronic hum or a wind noise.  We do not have the capability to remove ambient sounds involving multiple frequencies.

Photography Section
Forensic photographers use photography and videography to aid in documentation and reconstruction of crime scenes with specialized techniques. An example of forensic photography performed by the section is luminol blood visualization which allows crime scene investigators to see latent blood traces that are invisible to the naked eye. This technique is very sensitive and requires explicit photographic protocol to produce satisfactory results. The photographers also provide technical support to Crime Lab personnel with detailed evidence exemplars, presentations, and photographic documentation of crime scenes, including aerial views.

The section may also perform Image Enhancement which involves the application of digital techniques to isolate, clarify, or enlarge areas of interest for further examination or presentation in court.