Gwen Dunham is the owner of Discovery Investigations in Madison, Wis. She became a Certified Legal Investigator in 2007.

“Truth, like gold, is to be obtained not by its growth, but by washing away from it all that is not gold.” -- Leo Tolstoy

Our memories are like precious gems stored like veins of gold in deep, dark mines. They hold much of our identity in past events called long term memory. Short-term memory provides the passage through which information may pass into long-term memory. Although our memories seem to be safely stored we don’t want to forget them. So we lock our doors, record our history, save our photos, and create poetry and music to protect the memory of important events. Our selected memories are transferred into long term storage in our minds but also on computers, CD’s, DVD’s, books, and even in art galleries.

It seems that memory cannot be trusted. But a criminal defense investigator must be trusted to uncover the truth hidden inside the imperfect memories of defendants, witnesses and victims. In the quest for truth, memory, like a diamond, must be mined, examined, and rated for accuracy and credibility.

When a line of defense could be "false identification" an investigator will be particularly interested in the memories of the witnesses. But in nearly every case, part of the investigation involves exploring the memory of the defendant, witnesses and victims.

An investigator must consider that memory can be lost or changed so it should be handled delicately. What follows is an offering of how an appreciation of the vulnerability and importance of memory can aid an investigator during the many phases of a criminal investigation.

Memory is Imperfect

1) People can forget. This is common. Facts and events seem to become less available as time passes. However almost anything can retrieve a memory. Memories are often refreshed by cues, such as reviewing a report, memo or diary while a witness is in court. “Some courts have waxed poetic, declaring that the refresher could be ‘a song, or a face, or a newspaper item’ (Jewitt v. United States, 1926) or ‘the creaking of a hinge, the whistling of a tune, the smell of seaweed, the sight of an old photograph, the taste of nutmeg, the touch of a piece of canvas’ (Fanelli v. U.S. Gypsum Co., 1944).” Poets, musicians, playwrights, and novelists are fascinated with anything that recalls the past. In Thomas Wolfe’s, Look Homeward, Angel, Ben and Eugene talk of their imperfect memory. It sounds as if their memories are scrambled.

“Can you remember some of the same things that I do? I have forgotten the old faces. Where are they, Ben? What were their names? I forget the names of people I knew for years. I get their faces mixed. I get their heads stuck on other people’s bodies. I think one man has said what another has said. And I forget---forget. There is something I have lost and have forgotten. I can’t remember, Ben.”
“What do you want to remember?” said Ben.
“A stone, a leaf, an unfound door. And the forgotten faces.”

Sometimes an investigator can stimulate the memory of an incident as if a key opened the door to the memory of witnesses or victims. But an investigator must be careful to not offer new or phony information in attempts to stimulate recall because these details could unwittingly replace or scramble an original memory. The scrambled memory of an eye-witness could send someone to prison. Prisons are filled with thousands of people that were wrongly convicted.

As soon as the defense investigator is hired for a new case, he or she must begin the investigation as soon as possible because “time is of the essence in any investigation. After a period of time physical evidence disappears, the memory of witnesses fades….” as Anthony M. Golec, CLI, wrote in Techniques of Legal Investigation.

2) Witnesses don’t always pay attention. As criminal defense investigators we’re interested in what witnesses report using all of their senses. However, depending on the incident, they may have been distracted or otherwise impaired. Perhaps they weren’t wearing their glasses or hearing aids. Some people, even though they’re paying attention, cannot store new information due to Alzheimer’s, head injuries, or other physical or emotional conditions.

3) Memories constantly change with new stimuli: Although the sensory memory holds an image in rich detail, like a photograph, the image lasts here very briefly, and unless it enters short-term or long-term memory, it is lost. Thus, sensory memory is a sort of photographic memory. Interestingly, the sensory image from a sound disappears somewhat more slowly than the sensory image from a sight. The image in sensory memory fades quickly, and we then rely on that which has been transferred into more "permanent memory,” according to psychologist Elizabeth Loftus.

Since we’re selective about what goes into our short-term memory much of what witnesses are exposed to will never be available for later retrieval.

“Ordinarily, without rehearsal, short-term memory cannot retain anything for more than a half minute or so. One reason short-term memory is so important is that it plays a crucial role in conscious thought. Long-term memory is stored as bits and pieces of our experiences. The brain seems to edit some memories in order to remember others,” Loftus wrote.

Psychiatrists often focus on the impact of psychological defenses (repression or suppression) that seem to edit our memories. As a result some well-meaning counselors have elicited false memories resulting in false accusations, court cases and convictions.

4) Memories can be contaminated and false memories can arise: A criminal defense investigator must conduct careful interviews with defendants, witnesses and victims. The investigator asks open-ended questions (what happened?), selects neutral words that will not influence the memory, listens as the witness describes the incident, avoids leading questions and avoids asking the witness to ‘imagine’ their account because when someone is exposed to external or internal forms of suggestion, false memories can arise.

(Although imagination provides pieces of details, repetition of those details can turn those pieces into memory facts.) “If a particular case involves a fact situation where ample evidence of suggestion can be found, and especially when the case involves memories that are biologically, psychologically, or geographically implausible, these sorts of findings may help us all understand the construction of ‘memories’ that can occur in the mind of an individual who otherwise appears to be trying to tell the truth,” according to Loftus.

The importance of proper interviewing techniques impacted a Supreme Court decision in State v. Sargent, No. 97-554 (Supreme Court of New Hampshire, July 29, 1999). The court reversed a child sexual abuse conviction for failure of trial court to permit expert testimony on the possibility of false memory implantation in children through improper and suggestive interviewing techniques.

The investigator should instill the importance of not discussing the witnesses’ memory or statements with anyone. The investigator should make great effort to interview each individual alone because memories can be influenced when witnesses talk to one another or are told details or stories that conflict. This misinformation or the suggestions of others can change the outcome of a case.

In studies by Elizabeth Loftus, participants were given phony information that a car was white and that cars smashed into each other resulting in broken glass. As a result, those given the phony information tended to adopt it as their memory and those who were not given the phony information had more accurate memories. This study illustrates how misleading information can influence the memory of a witness when they are interviewed in a suggestive manner, when they talk to other people who give their version of the events or offer phony information. Memories can become distorted.

In addition, Loftus discovered that entire memories could be created for an event that never happened. Loftus created an experiment that resulted in 25% of participants believing that they were lost-in-the-mall at age 5 or 6. They even added embellishing details to the day at the mall. In another study, Loftus (Braun, Ellis, & Loftus, 2002) planted a false memory leading initially 16% of participants to believe they met Bugs Bunny at a Disney Resort. This was not possible because Bugs Bunny is a Warner Brothers character and would not be at Disneyland.

False memory may develop from a mere suggestion that leaves a memory trace in the brain. As time passes the suggestion tag slowly deteriorates and the memory of a real event becomes confounded with the false memory. Loftus said, “The resulting memory can even be embellished with snippets from actual events, such as people once seen in a mall. Now you ‘remember’ being lost-in-a-mall as a child.”

Memories do not exist in a vacuum. They continually disrupt each other through a mechanism called “interference”. Our memories can be disrupted earlier or later. The new post-event information often becomes part of the memory by supplementing or altering it, sometimes in dramatic ways, according to R.L. Greene, author of Human Memory.

5) It’s difficult to distinguish between false memories and true ones: The results of the Loftus “Lost-in-the-Mall” study included differences between the true memories and false ones; participants used more words to describe the true memories, and they rated the true memories as being somewhat more clear. Other studies indicated that imagining the event raises confidence the event occurred, makes the event more familiar, and the more times the action was imagined the more likely they were to remember having performed it.

“Psychological science has not yet developed a reliable way to classify memories as true or false. Moreover, it should be kept in mind that many false memories have been expressed with great confidence." Loftus made this point in 2003, writing in the journal Science and Society, on the topic: “Our Changeable Memories: Legal and Practical Implications.

6) Police reports may be inaccurate memory accounts: Not all accusations are true. Witnesses and/or victims can suffer from mental illnesses and/or be misled by irresponsible therapists or police officers or significant others into developing false memories. The accuser may genuinely believe it is true or may lie in order to make the false accusation for some unknown reason. The investigator will sometimes strengthen the case if a reason for the possibly false accusation or recantation is uncovered.

Not all confessions are true. Sometimes people confess to crimes they didn’t commit or even crimes that never happened. Some people, especially highly suggestible individuals, after intensive questioning, may come to believe they committed a crime and confess to it. An investigator needs to be aware of proper or improper police procedures that might drastically affect testimony.

7) Various factors affect memory of a crime: Identification errors increase with: stress, weapon focus, intoxication, different race faces, one-person show-ups vs. photo spreads/line-ups, distracters do not resemble suspects, age (young or old are less accurate), decreased amount of time observing suspects, prior exposure to mug shots of innocent suspects, poor attitude, contact with suspects in other contexts, identification instructions and interview questions worded suggestively or otherwise misleading and memories that are only recovered not continuously remembered. Eye-witness confidence in the accuracy of their identification is influenced by other facts than accuracy and is not a good predictor of actual accuracy. The rate of memory loss is greatest right after the event and then levels off. These points are made by C.J.Brainerd and V.F. Reyna in The Science of False Memory.

Memories are Accessed Every Day

Although our memories are imperfect we rely on them every day. Each moment our memories remind us who we are, where we are, and what we want. And with that input we’re able to use our imagination to create our world. Our society teaches us that what we can imagine, we can achieve.

An investigator often imagines how a particular incident might have happened in order to solve a case, but in the end the truth tells the real story.

Unfortunately it is often a matter of what one believes to be true rather than what is true that determines how people will act in a given situation. Eye-witnesses who identify innocent defendants are not liars because they usually believe in their memory. “That’s the frightening part-- the truly horrifying idea that what we think we know, what we believe with all our hearts is not necessarily the truth," according to J. Neimar, writing in Psychology Today.

Let us, as investigators, be fearlessly vigilant in our efforts to chip away until all that remains is gold.