Congratulations to our investigator Brandé Micheau for receiving her certification as a forensic testimonial evidence recovery interviewer. Brandé worked incredibly hard studying witness interview strategies, the component methods of an investigation, ethical considerations, and visual imagery techniques in order to pass the CFI-FTER exam and receive this very reputable certificate.
Cellular carriers store a wide variety of information about how, when, and where customers use their cell phones. A search warrant or subpoena to the carrier can return (among other things) Call Detail Records (CDRs), which describe calling and TXT’ing activity.
Extracting probative findings from CDRs requires an understanding of how cellular networks are designed and operated, as well as knowledge of how CDRs can, can’t, and shouldn’t be used. Because of this, many defense teams aren’t leveraging the CDRs frequently found within discovery, even though they may hold exculpatory or mitigating evidence.
Armistead Investigators has the tools, expertise, and insights necessary to assist with cases involving CDRs. This article provides a brief, and in places over-simplified, introduction to working with CDRs.
Cellular Networks 101
Cell towers are everywhere. The diagram below shows the locations of one carrier’s towers around the Denver and foothills area. Note how the tower spacing varies, depending on factors like population and terrain.
Each cell tower typically holds several antennas each designed and precisely pointed to provide high-quality, highly-reliable communications for a finite area around the tower. While carriers disclose the direction each antenna points, they won’t reveal its exact coverage area (they consider that to be proprietary information).
An antenna’s coverage area can be estimated, however, using knowledge of tower spacing and common antenna design parameters. The diagram below shows the estimated coverage areas of two antennas on a tower along I-70 near Evergreen.
What’s in a CDR?
CDRs are provided in a big table (typically a spreadsheet). This table documents activity for a single phone number for a given period. In simple terms, there’s a row for each call or TXT, and numerous columns containing metadata about that call or TXT.
While each carrier provides different metadata, the following information is almost always present in some way, shape, or form:
- Date and time
- Incoming and outgoing phone numbers
- The geographic location of the cell tower(s) the phone used
- Which antenna(s) on the tower(s) the phone used
Approximating Phone Location From CDRs
Because the CDR tells us the location of the cell tower a phone used at a particular date and time, the phone must have been in the general vicinity of that tower. But the CDR also indicates the antenna(s) the phone used; doesn’t that help refine the phone’s location? The answer is “possibly,” after taking into account factors such as:
● We don’t know the exact coverage area of the antenna
● Radio signals can be reflected and bent ... meaning the phone might be close to, but not actually within, the antenna’s coverage area
On the flip side, knowing the antenna(s) used can also be extremely revealing. Refer back to the antenna coverage diagram above. If a CDR showed that the phone used both antennas during one short call, it would be reasonable to place the phone in a car driving along I-70.
One of the more interesting applications of CDRs is to infer the day-to-day behavioral patterns of a person. Given enough CDRs, and the assumption that a person always has their phone with them, one can determine:
- Areas the person frequently visits
- Days and times they typically visit those areas
- The people most often communicated with
- Where they “lay their head” at night (inferred from the phone’s use of the same antenna from the evening through the next morning)
Armistead Investigators can assist our clients with many aspects of working with CDRs, including:
- Formulating technical language for preservation letters and subpoenas
- Interpreting, and possibly challenging, law enforcement findings
- Creating maps and animations showing a phone’s location
- Gleaning investigative leads
- Conducting Pattern-of-Life analyses
If you’d like to chat about a case involving CDRs, contact Chris Wells, the senior digital investigator for Armistead Investigators, at firstname.lastname@example.org or 303-825-2373 ext. 5.
Whether to record witness interviews is often a subject of debate between and among investigators and attorneys. From my perspective, I do not think there is necessarily a right or wrong answer, but I typically prefer and recommend that my investigators do not record interviews, particularly in criminal matters.
I firmly believe a recorder creates a barrier between the witness and investigator, and prevents a forthright exchange of information. A witness is more likely to be guarded about what they say when there’s a recorder in front of them, and may include information that is irrelevant and distracting to the issue at hand. Extraneous information is particularly burdensome in cases where a defense witness statement may become discoverable, as the unrelated issues they bring up can provide fodder for harassing cross-examination.
“Extrapolation of a later alcohol test result, to the time of the alleged offense, is always of uncertain validity and therefore forensically unacceptable.”
-Kurt M. Dubowski, Ph.D.
The use of retrograde extrapolation (RE), or “back calculating” an individual’s blood alcohol concentration (BAC) in criminal matters, has many proponents and critics. Though prosecutors will often attempt to have RE in cases involving alcohol, some leading world scientists have strongly criticized the practice, noting there is rarely enough information and data available to backtrack an individual’s BAC to the time of the alleged offense.
RE is calculated by using the Widmark equation, which is most accurately done using multiple results from draws over a period of time, or by assuming the rate of elimination falls within an average rate of 0.010-0.025g ethyl alcohol/100mL blood per hour (Jones 2010). However, in order to accurately calculate RE, an individual must be in the post-absorption phase and their BAC curve must be linear.
The rate of alcohol absorption for an individual is heavily based on many factors such as food intake and the type and concentration of the alcoholic beverage. Sex, body weight, body water and other physical, biological and psychological factors also vary widely. Even in some of the most controlled experiments, elapsed time from end of alcohol intake to peak blood alcohol concentration can vary by more than two hours. The validity of calculating RE depends wholly on the accuracy and completeness of known variables, some of which might be identified in police reports and witness statements.
I am constantly asked, “How did you go from law enforcement to criminal defense?” or, “How can you be on the dark side?” These comments come from other present and former law enforcement officers and prosecutors, but also from friends and the public.
While I was in the police academy as a 22-year-old, a wise forensic pathologist told my class, “Before I start an autopsy, I always remember that once, this was some mother’s baby.” Those words have stuck with me through 18 years in law enforcement and 26 years as a criminal defense investigator.
While not always easy, in the heat of a fight/arrest I would try to remember this adage—if not during the fight, then afterwards once things had calmed down. I remembered it when I lifted up a client – a terrorist I had helped defend – from the execution table following his execution. I have investigated cases for attorneys who represent some of the worst criminals in the country. Two of my clients have been executed and several are on death row. Some of these people are not likable, and even when they are, it’s impossible to square with what they have, or are alleged to have, done.
How did I make the transition to what many law enforcement officers refer to as “the dark side?” There are several factors, but the most influential was remembering the adage of that pathologist: “This person was once some mother’s baby.”
The criminal justice system is, for the most part, an adversarial system—and should be. I’ve worked in criminal justice all my adult life – over 40 years – for both the prosecution and the defense. I believe that experience allows me to make some observations.
When I worked as a police officer and later as an investigator for the district attorney, I had one goal: Solve crime and put people in jail. What was missing was that I knew little or nothing about the individual I was pursuing. Sure, I knew a crime had been committed and sometimes I knew why; but seldom did I know much about the individual charged. To be honest, I really didn’t care—they were just a number and I moved on to the next case.
In later years, I became a legal investigator and, because of my background, focused on criminal defense investigations, working for criminal defense attorneys and their clients. In this capacity, it’s my job to know the most intimate details of the accused’s background. I’ve met family and friends and often spent a lot of time with the accused. I’ve learned that everyone is different, with an individual background and life history.
Yet as I look at the system, it seems to treat everyone alike, and many prosecutors and defense attorneys only want to fight. The result is an unfair administration of justice.
Whether it’s false claims, securities fraud or money laundering, corporate fraud is an alive and well business model in the United States and around the world. Regardless of whom the victim or client is, the following are steps that can be taken towards digging into corporate fraud investigations.
First, consider the varying regulations in states in which the company operates. Determine whether certain states require stricter laws in reporting and operations and focus on states from each end of the spectrum. For example, when it comes to corporate healthcare, pharmaceutical drug companies or medical device companies, Texas and Florida have the most lax laws, while states like California and New York are on the opposite end of the spectrum.
Spend some time understanding what public data might be available and where. If you need to FOIA records from city, state or federal government agencies, try calling whomever will be receiving your request prior to your inquiry and reference your phone call in your written request. Sometimes a personal touch can help reduce the weeks to months to years long waiting process and/or set you up for fast track requests and responses next time around. If you're told you're not allowed to access particular data or information, be sure to ask why as well as what information is available. (See FOIA example here.)
Rachel and I just returned from the mid-winter NALI conference in San Diego. We go to these training meetings for the benefit of our clients.
The training we received included:
• Shooting Incidents and Surveillance Video Analysis
• Investigating Police Misconduct
• Vehicle Incident Reconstruction
• Examining Forensics
• Representing Mexican Nationals
• Pitfalls in the Attorney/Investigator/Expert Working Relationship
• Discerning Issues in the Concept of Habeas Corpus
We also networked with professional investigators from around the country and even Europe, so that we know who to call on for help in out-of-state or international investigations.
As the holidays approach and the gift of giving is on your mind, be wary of those lurking on the naughty side of Santa’s list!
This year, the National Retail Federation is forecasting holiday sales in November and December to reach as much as $117 billion online and $655.8 billion overall.
Protect yourself and your wallet by being aware of some of these common holiday scams.
Watch out for fake shipping notifications and take steps to reduce the risk of package theft when sending or receiving gifts. Track deliveries online, provide delivery instructions to leave packages out of sight and try to select a delivery option that requires a signature. Insure valuable packages and bring them to a shipping facility rather than leaving them outside for pickup. Show off a home security sign in your front yard, whether you have one or not.
The best way to protect yourself as a consumer from a data breach is to shop in-store and pay cash, but for a lot of shoppers this is often unrealistic. When shopping online, pay attention to URLs and emails that contain well-known brands with extra words. If you’re unsure, Google an unfamiliar retailer, an email and/or URL to see if anyone has flagged it as a phishing scheme -- chances are someone has been scammed before you! Look for a lock symbol and “https” in the URL address. Watch out for shipping notifications with attachments and links that will download malware and attempt to steal your passwords. Use unique passwords for all of your accounts and safeguard them in a password manager like LastPass.
From time to time I see inquiries from attorneys on various listservs looking for investigators from out of state and sometimes from out of the country.
Hiring an investigator you don’t know can be tricky and fraught with danger. Going to the yellow pages or the internet is dangerous. Even more so when you are trying to deal with someone outside of the country. Out of country investigations are especially problematic. Language and customs are always a concern as well as regulations in each country. It is easy to get ripped off if you are not careful and don’t know who you are dealing with.
Unfortunately, private investigation draws its share of inexperienced, unethical and just plain incompetent people. Don’t be fooled by slick webpages and advertising. Remember, once you hire these people they are acting as your agents and their conduct could affect your law license.
The Investigative Process and The Attorney Series - Part 4
The fourth step in the investigative process is writing the report of the interview. This may be the most critical step in the process.
We generally write our reports in the first person and include them as a summary of the interview, followed by bullet points of what the person relayed to our team. If there is an exact quote we place the quote in quotation marks.
We include int the report everything the person divulged, both good and bad. It is essential that the attorney receives not only the good, but the bad information that a witness may have brought to the table. In criminal defense work, often the information from the subject is bad, but there’s the old adage that “bad can be good.” There is nothing worse than being surprised by a witness on the stand who had bad information that an investigator did not relay to you.
All of the reports should be labeled attorney/client work product.
In our reports, my preference is that the report contain the following paragraph: “This report has been prepared for counsel and is subject to the protections of the attorney/client privilege and the attorney work product doctrine. Information obtained during the interview has been reorganized and summarized for clarity and is not a verbatim transcription of the interview. The report contains no impressions, thoughts and analysis of the information provided by the witness.”
In reality we do not include in our reports personal mental impressions and thoughts about a witness. These are presented in a separate memo to the attorney in case the report ever has to be discovered.
The report should not contain a lot of extraneous information, but rather, information pertinent to the topic and subject at hand.
It is impossible to record exactly what someone says, and if that is the goal, then a tape recorder, with the permission of the person being interviewed, should be used. We believe that recorders generally hinder the transfer of information and make the subject more cautious with their words. As indicated earlier, we prefer the summary technique and require the attorney meets the witness, if possible, before placing them on the stand.
If there is a conflict we are ready to take the stand and testify.
The Investigative Process and The Attorney Series - Part 3
Locating and interviewing witnesses is the most critical step in most investigations. It takes a skilled, even handed investigator to locate and interview witnesses, many of whom do not want to be found or interviewed.
Locating witnesses can be as easy as looking at a police report or other official document to having to conduct an in-depth skip trace. At Armistead Investigators, we subscribe to numerous proprietary databases that aggregate millions of records that assist us in locating witnesses.
Given the events of last week, I feel compelled to speak my mind. Some of you will agree and some will disagree. That’s ok. We need constructive debate.
I approach this subject as a former law enforcement officer and currently as a criminal defense investigator.
I have been on "both sides of the fence” and have friends and colleagues on both sides as well. I have also served as an expert witness in police use of force cases, including deadly shootings. I have the utmost respect for the law enforcement officers who put their lives on the line every day to protect us.
We have heard the line that it is easy to underestimate the real and ever present danger these officers face. One moment of carelessness can, and often does, lead to death.
Seventeen years ago today I was in the Riverside, California jail visiting a client who was facing three murder charges out of the State of Colorado. He was soon to be extradited back to Colorado where he would face the death penalty.
As I was being escorted from the jail, one of the deputies, who knew I was from Colorado asked me, "Have you heard what happened back there?" I replied, "No" as I had been in the jail for several hours. He told me there had been a mass school shooting, that several people were dead, and that it was all over the news.
I left the jail and went to my rental car and noticed my pager was going off, with messages to call the office ASAP, which I did. Upon reaching the office I was transferred to my managing investigator, Jennifer Gedde (now a lawyer in Denver) who told me quickly about the shooting and that our firm had been retained by one of the suspect's lawyers. Jennifer was with the suspects parents at the time we spoke. I drove to the airport and caught the first flight back to Denver. Upon arrival in Denver I was directed to go to a room in a downtown hotel. Upon arrival at the room I found several members of my staff along with the parents of one of the suspects.
Jennifer told me that she had confirmed both suspects were dead but the lawyers wanted us to stay with the parents, protect them and be available for any investigation that might be necessary on behalf of the parents. The press were looking for the parents, but they were checked into the room under my name.
The National Registry of Exonerations has recorded more than 2,000 people who have been exonerated of the crimes for which they were convicted. This means these people spent countless years in prison for a crime they did not commit. These are not people who got off on some legal technicality, but actually innocent people.
How does this happen? One of the culprits is eyewitness identification. Yet, research has revealed that eyewitness identification is wrong approximately 50% of the time.
I am often asked, as a legal investigator, the nature of my job. “What do you do? Do you chase people around? Do you peep in their windows, looking for their cheating husbands or wives?"
It is an interesting question that invariably leads to interesting conversation. While, because of the nature of my work, I cannot reveal the details of my cases, I can discuss “what I do.”