What Makes an Expert?

According to Merriam-Webster, an expert is defined as "one with the special skill or knowledge representing mastery of a particular subject." Similarly, Cornell Law School defines an expert witness as "a person with specialized knowledge, skills, education, or experience in a particular field who is called upon to provide their expertise in legal proceedings to assist the court with understanding complex technical or scientific issues."

The critical elements here are "mastery" and "specialized knowledge." Consider the following scenarios to identify the expert:

1. In the field of home design:

   • Option 1: A university professor with a degree in architecture and 30 years of experience designing homes.

   • Option 2: An individual who has taken a few architecture courses and designed their own home using purchased drawings. Clearly, the professor is the expert.

2. In the domain of wireless technology:

   • Option 1: An engineer with a degree in the field, experience working for several wireless technology companies, advanced coursework, and a track record of designing, testing, and troubleshooting wireless systems.

   • Option 2: A law enforcement officer with a degree in an unrelated field, such as criminal justice, who has taken a few courses on cellular technology and uses forensic software. Again, the first individual is the expert.

     
     

A true cellular technology expert possesses specialized knowledge, extensive field experience, and a deep understanding of the subject. Having attended a few classes or using forensic tools alone does not suffice to meet the standard of expertise. While law enforcement professionals might interpret data in the context of an investigation, they are not qualified to explain the nuances of cellular networks or how phone records relate to them.

Key Issues in Cellular Data Analysis   One of the most critical aspects of legal cases involving cellular technology is coverage. Call Detail Records (CDRs) provided by cellular carriers include tower locations, antenna directions, and timestamps of calls, texts, or data sessions. This data can be plotted on a map, but it does not indicate the exact geographic area the tower's antenna covers (its coverage area). Accurate understanding of coverage areas requires expertise in radio wave behavior and cellular technology.

Unfortunately, law enforcement personnel posing as "experts" often present coverage interpretations based on arbitrary assumptions rather than data, misleading the court. This practice is unfair and compromises the judicial process.

Another complex aspect is the use of Time Delay of Arrival (TDOA) for estimating phone locations. TDOA relies on calculating the distance traveled by radio waves and using triangulation to approximate the phone's location. While the concept appears straightforward, it has many limitations. Factors such as radio interference, error correction schemes, and variations in digital cellular technologies all impact the accuracy of these estimates. Cellular carriers use proprietary methods to improve accuracy, but understanding these intricacies requires deep technical expertise.

Choosing the Right Expert Witness   To select a qualified cell phone forensic expert, consider the following criteria:

1. Educational Background: The expert should have a degree in engineering or a similar scientific discipline. A strong scientific foundation is essential for understanding the technology at its core.

2. Practical Experience: Look for extensive hands-on experience in cellular networks, combining formal training with fieldwork. The ability to test and analyze how networks function in real-world scenarios is crucial.

3. Industry Respect and Communication Skills: The expert should be recognized in the industry and have prior experience as an expert witness. They must be able to present complex information in a clear, straightforward manner.

The Current Reality in Legal Cases   In most cases I've handled, the opposing "expert" is a law enforcement official. Unfortunately, these individuals often focus on irrelevant or inaccurate technical details, wasting the court’s time and presenting biased interpretations. If both sides were to rely on genuine experts with a proper understanding of the issues, the process would be more efficient and fair, ensuring that the presented data serves the pursuit of justice rather than hindering it.