Considerations with Respect to the Use of Evidence During an Investigation

The Reid Technique represents a structured investigative approach to solve cases involving little or no evidence. The first step of the technique is factual analysis in which the investigative information is analyzed to identify possible suspects and assess each suspects' probable involvement in the offense. The second step is the interview of possible suspects to develop additional investigative information and behavior symptoms indicative of truth or deception. When a suspect exhibits deceptive behavior during the interview, the investigator may move into the final step of the technique which is to interrogate that person. The interrogation is conducted in an effort to learn the truth from that individual. In some cases an investigator is able to gather enough evidence of a suspect's guilt that a confession is not needed to successfully prosecute that person. Collecting prima facie evidence of a suspect's guilt, however, is a rare occurrence. In most cases the investigator only obtains circumstantial evidence that points toward a particular suspect's probable involvement in a crime. In other cases, there may be limited physical or testimonial evidence that further implicates the suspect. This web tip will offer recommendations on the use of such evidence during the course of the investigation.

Recommendation #1 When inviting a non-custodial suspect in for a voluntary interview, do not mention specific evidence that points toward that person's guilt.

There are basically two reason why guilty suspects voluntarily agree to be interviewed or take a polygraph examination. The first is the belief that they can lie without being caught. The second is that they do not want to incriminate themselves by being the only person who is not cooperating with the investigation. However, this entire thought process changes considerably when the investigator reveals incriminating evidence to a suspect. Consider the following invitation for a voluntary interview:

"Jim, I need to talk to you about a robbery of a gas station clerk last Friday night. You already have a record for robbery and we have two witnesses who saw you drive away from the gas station right after the robbery. In addition, I know that you have been spending a lot of cash since the robbery. What time can you come in and talk to me about this?"

No suspect in his right mind would agree to meet with this investigator. The suspect has little choice but to believe that the investigator is already convinced of his guilt. In addition, this invitation leaves little doubt that the suspect is the only person being considered as guilty of the robbery. Under this circumstance, most guilty suspects would force the investigator to prove a case against him and not cooperate with the investigation. A much more productive invitation to this suspect would be as follows:

"Jim I am investigating a situation where some money was taken from a gas station clerk last Friday night. I am in the process of scheduling preliminary interviews for people who were seen around the gas station that night. Your name has come up on that list and I was wondering whether you could come in and talk to me about this?"

This invitation is much more likely to result in the suspect agreeing to submit to a voluntary interview for two reasons. The first is that the suspect believes there is no real evidence pointing toward his involvement in the robbery, thus increasing his belief that he can lie successfully during the interview. Secondly, the suspect does not want to incriminate himself by being the only person seen around the gas station that night not to cooperate with the investigation. During our seminars we emphasize that an investigator is much more likely to elicit the truth from a suspect who voluntarily agrees to be interviewed (where Miranda warnings are not required) than a suspect who is taken into custody. Remember that just because an investigator has probable cause to arrest a suspect, he is not obligated by law to place that suspect in custody.

Recommendation #2 During an interview, never bring up evidence until first giving the suspect an opportunity to tell you about it voluntarily.

A common mistake investigators make during an interview is introducing evidence prematurely. Consider a hit and run case where the investigator knows, from talking to a body shop mechanic, that the suspect replaced a headlight and damaged grill on his vehicle three days after the accident. The suspect told the mechanic that the damage occurred in a parking lot where someone must have backed into his car. If, during the interview, the investigator shows the suspect a copy of the work order and asks him to explain how his car got damaged, obviously the suspect will relate the same story he told the mechanic. However, if the investigator first asks questions along the following lines, much more meaningful information may be learned:

Q: "Have you been involved in an accident at all in the last two weeks?"
Q: "Has your car received any damage in the last two weeks?"
Q: "Have you had any repair work done on your vehicle in the last two weeks?"

An innocent suspect, who was in no way involved in the hit an run accident, will respond truthfully to these questions and relate details of the parking lot incident and repair work done. The deceptive suspect, not wanting to incriminate himself, is likely to answer "no" to these questions. It is an axiom of detecting deception that a suspect who lies about small events is likely to be guilty of the crime. However, the investigator must invite the suspect to lie. To do this, evidence revealing the truth (witness statements, past arrest record, recent purchases, etc.) must be withheld from the suspect during the interview at least until the suspect has first been given the opportunity to tell the truth on his own volition.

Recommendation #3 Use evidence strategically during an interrogation.

The vast majority of interrogations are conducted on suspects for whom there is insufficient evidence to prove guilt beyond a reasonable doubt. Before a suspect will accept the consequences of his crime by telling the truth, he must first believe that there is already a high probability that his guilt has been, or will be established. If an investigator begins an interrogation by laying out circumstantial evidence that tends to implicate the suspect's possible involvement in the offense, the suspect will immediately recognize that there is insufficient proof of his guilt to obtain a conviction. Consequently, early introduction of evidence during an interrogation often reveals the weakness of the investigator's case. In addition, when an investigator reveals specific evidence during an interrogation the suspect has something tangible to attack as the following dialogue illustrates:

I: "Joe, you told me before that you didn't have any body work done on your car yet I know that you had a front headlight and grill replaced at the local Buick dealer three days after this accident. I talked to the mechanic who did the work and have a statement from him so don't lie and tell me you didn't hit that man."

S: "Let me explain something to you. First, I did not hit the man and I don't know anything about that. You're right in that I didn't tell the truth about the repair work. I thought it would make me look guilty so I didn't tell you. But I didn't hit that guy with my car."

This suspect is unlikely to tell the truth about his involvement in the hit and run accident. He now knows that the only evidence the police have is the repair work done on his vehicle and he can easily explain it away. Consider, however, that the investigator initially withheld this evidence and used it more strategically later during the interrogation as illustrated:

I: "Joe, I think you responded as anyone else would have under the circumstances. This guy is out walking in the dark, wearing dark clothes and he's been drinking so he's staggering all over the road. You are driving by and he practically walks right in front of your car and this thing happens. At that point you got scared and continued driving. Most people would have done exactly the same thing."

S: "What proof do you have that I did this?"

I: "I would love to sit down and go over with you, piece by piece, all of the evidence that we've collected on this case but it's against department policy for me to do that. Eventually, of course, you'll have a chance to see all of the evidence but by then my report will be submitted and it will be out of my hands. Joe, you're not some sort of clever criminal who has done things like this your whole life. When something like this happens to an average guy like you and me we don't know enough to cover our tracks. A criminal would have taken his car out of state to have the headlight and grill replaced. You had it done at the Buick dealer right here in town three days after the accident. A criminal would have gone back and collected the parts of the grill from the accident scene so they could not be matched with the broken grill that was replaced. Again, I can't discuss the specific evidence with you, but what I think will be important to bring out is whether or not you were purposefully aiming your car at this guy or if it really was just an accident..."

A successful interrogation relies extensively on pretense and innuendo. If circumstantial evidence is introduced at all, it should be mentioned in passing as if it is the icing on the cake. It doesn't take a skilled defense attorney to successfully attack circumstantial evidence - most criminal suspects are quite capable of doing this on their own. Furthermore, it has been our experience that interrogations centered around incriminating evidence are the most likely to involve illegal threats and promises of leniency from the interrogator. Frustrated by the suspect's perhaps implausible but possible innocent explanation for the evidence, the investigator resorts to tactics that may well cause a subsequent confession to be suppressed as evidence in a court of law.

In conclusion, despite television portrayals of investigators routinely gathering overwhelming forensic evidence of a suspect's guilt, in real life the most common form of evidence admitted at trial is the spoken word. Examples include a victim's physical description of the defendant, eye witnesses who can identify the defendant, witnesses who refute the defendant's alibi, witnesses who offer testimony relating to the defendant's motive or propensity to commit the crime and the defendant's confession. Because investigators often only develop evidence that tends toward proving a suspect's involvement in a crime, but is insufficient to prove guilt, the evidence must be used judiciously. In some cases, an investigator is better off not mentioning circumstantial evidence at all. Remember the adage that it is sometimes better to remain silent and be thought a fool than to open your mouth and remove all doubt.