I, Spy: How to Be Your Own Private Investigator: New Excerpt

I, Spy: How to Be Your Own Private Investigator by Daniel Ribacoff is the quintessential book for the armchair detective that wants to become their own private eye!

Have you ever wanted to be your own private eye? Have you ever wanted to track down long-lost relatives or people who've scammed you? Have you ever wanted to know if your kids really are where they say they are? Or if your significant other is cheating on you? Or how to locate assets in order to collect on a judgment?

In I, Spy, world-renowned private investigator Dan Ribacoff will show you how. With decades of experience in public safety, private investigation, and credibility assessment, Dan will teach you:

The do's and don'ts of surveillance
How to conduct a stakeout—from what to wear to what to bring
How to track down anyone anywhere
How to collect and interpret evidence
How to tell if someone is lying
How to utilize informants
How to protect your home, your valuables, and your privacy
How to go off-grid, for now or forever
How to know if you're being stalked
The fundamentals of garbage retrieval
And much, much more!

Learn the art of private investigation from a pro. With Dan's time-tested tips and stories of true crime detection—straight from the gritty streets of New York City—you'll be hot on the trail in no time!


Private investigation is the art of detection. Investigators spend much of their time physically tracking people down in order to expose their whereabouts. However, private investigation is also the art of exposing people’s characters—are these people telling me the truth? Are they who they say they are? Can I trust them? What are their motivations? Are they going to rip me off? Cheat on me? Hurt my kids? Are they friend or foe? While private eyes are out there conducting subterfuge—lying, pretending—in order to achieve an objective, they’re also trying to figure out whether others are doing the same to them.

In the business, we refer to this as credibility assessment: a psychological detection of deception. It is the monitoring and evaluation of not only a subject’s spoken words, but the way those words are spoken, the absence of them, the time it takes for a person to say them, and the facial expressions and body language associated with them. Many types of people use credibility assessment, from law enforcement officers to mental health physicians and psychologists to juries, who, not unlike citizen private eyes, use it to determine a person’s innocence or guilt. The techniques of credibility assessment are applicable to practically any situation:

  • A woman confronting her husband who she suspects is having an affair.
  • A parent having a talk with her teenage daughter, who she suspects has crashed the family car.
  • An employer interviewing an employee after a coworker accuses him of slapping her butt at the water cooler.

Assessing credibility is something that we do on a daily basis. I will teach you to become better at it.


There are two main ways to solicit information from someone during conversation:

  • Interview: An informal question-and-answer session. An interview may be performed with a suspect, a victim, or a witness to a crime (even if the crime is stealing cookies from the cookie jar).
  • Interrogation: A formal and systematic question-and-answer session. The purpose of an interrogation is to elicit a confession from a person, often a suspect. You know the guy did it and you want him to admit it.

Both interviews and interrogations have certain procedural strategies:


1. Interview

Goal: To gather information and perform a credibility assessment. Think of it as a fact-finding mission.

Tone/demeanor/body language: The tone of an interview is non accusatory. We’re just talking. Nothing to be alarmed about. Subtly adjust the tone, volume, and speed of your voice as well as your body movements and gestures so that they mirror, or match, your subject’s. (For example, if the subject uses hand gestures, use them too. If he has his legs crossed, cross yours too.) This will help to develop a rapport and make the subject feel more comfortable, which increases your chances of eliciting information. Even if you know a subject is lying to you or is exhibiting a clear indication of deception, play it cool. The goal is to keep the subject talking in order to answer your questions.

Location: Interviews should be performed in a neutral setting. An employee lounge. A living room.

Positioning: You and your subject should be comfortable, with ample room for each. However, there should be nothing between the two of you, so you can accurately gauge his body language.

Amount of speaking: During an interview, the investigator should speak 5 percent of the time. Investigators or law enforcement officers usually conduct what are called narrative techniques—they let suspects or subjects go on and on without interruption in hopes that they will say something incriminating or contradictory. Therefore, stay away from yes-or-no questions and try to keep your questions succinct: As far as your subject knows, you have no idea, for example, that he stole money from petty cash or scammed Old Man Jenkins out of his Social Security check, but if you reveal too much info in your line of questioning and he gets the slightest whiff that you’re on to him, he’ll clam up.

2. Interrogation

Goal: To persuade the subject to tell the truth or admit wrongdoing.

Tone/demeanor/body language: As with an interview, you want to begin with a non-accusatory manner. Speak kindly, softly. Mirror and match their voice and body movement. For some subjects, you will continue like this throughout the interrogation. You’ll express understanding toward your subject’s behavior, because, psychologically, it’s easier for a subject to come clean when another person appears to identify with why he has done what he’s done. For other subjects, you’ll need to become incrementally more aggressive in order to elicit a confession. It’s important to constantly gauge your subject and make adjustments based on his responses.

Location: Interrogations should be performed in a setting where the questioner or interrogator has the home-court advantage. Law enforcement officers will conduct interrogations in the lock up. In the civilian world, it might be the boss’s office, the principal’s office, or a dad’s home office.

Positioning: As with an interview, there should be nothing— no desks or coffee tables—between you and your subject. During the course of the interrogation, you’ll want to encroach incrementally on a subject’s personal space; you want to lessen the distance between you. This will create a feeling of intimidation in the subject, a feeling that there is no protection and nothing to hide behind.

Amount of speaking: The investigator should speak for the vast majority—or approximately 95 percent—of the time. Also, there should be no accusatory questions, at least until the very end when you think your subject is ready to confess or tell the truth. Instead, think of an interrogation as a monologue or a presentation of a report—you are making statements, not threats, which are designed to persuade your subject to tell the truth:

  1. 1. Address the reasons why the interrogation is taking place— there is money missing from the petty cash box, an unexplained absence from school, or a new bruise on your son or daughter.
  2. 2. Present the evidence—a security camera image of your subject opening the petty cash box, witness testimony that your subject has been skipping school, or photos of welts on your child’s face.
  3. 3. Make a logical or rational argument for the person’s guilt. I could see why you would want to steal…I was a teenager too, once…I know, parenting is difficult.


Human beings use the same subconscious strategies to deceive—certain words and phrases, sentence structures, and types of content. Whether the question is being asked to your child, your wife, a guy you met at a bar, a prospective employee, or a college professor, you want to listen to what a person says and how he or she says it. Years of research have identified the linguistic signals that differentiate deception from truth. Your job as a private investigator is to discern them.

1. Evasion

People who are guilty have a hard time saying no. Instead, they answer a question with a question or avoid the question altogether.

Interrogator: “Did you ever commit a crime?”
Suspect: “Do I look like somebody who would commit a crime?”

Interrogator: “Did you sexually molest that girl?”
Suspect: “Why would I molest a girl? I have a beautiful wife. I get all the sex I want.”

2. Hesitance/latency and/or filler words

Delayed responses or the use of filler words or stall tactics—um, you know, excuse me—afford a subject more time to come up with a plausible lie. If a person doesn’t answer your question with confidence and assurance, it should be considered a red flag. Law enforcement officers look for this kind of thing all the time in trying to detect probable cause for further investigation.

Scenario #1

Officer: “Excuse me, miss, what are you doing in this neighborhood?”
Suspect: “I’m going to see my grandmother. She’s lived here forever. She won’t move.”
Officer: “What’s your grandmother’s name?”
Suspect: “Suzie Smith.”
Officer: “Where does she live?”
Suspect: “123 Main Street, Apartment 8.”
Officer: “What are you doing for grandma?”
Suspect: “I’m bringing her medicine from CVS.

This woman seems believable. There’s no latency, no hesitation, and her story makes sense. Therefore, there’s no probable cause. She appears to be telling the truth.

Scenario #2:

Officer: “Miss, what are you doing in this neighborhood?”
Suspect: “Why? Um, I’m…I’m…um, visiting my grandmother.”
Officer: “What’s your grandmother’s name?”
Suspect: “Her name? Her name is…um, Sara.”
Officer: “Where does Sara live?”
Suspect: “Oh, um…Over there in that building.”
Officer: “What apartment?”
Suspect: “Excuse me?”
Officer: “I asked what apartment, miss.”
Suspect: “You want the number? Wait, I can’t remember the floor…”
Officer: “Would you mind stepping out of the car?”

This simple exchange produces probable cause for the officer to check this woman out. She is exhibiting clear signs of deception, and he has been trained to recognize them. I had a highway cop in my office one day. I was polygraphing his girlfriend, because he had strong suspicions that she was cheating on him. He goes to me, “I don’t know why she didn’t think I would know. I get lied to a hundred times a day: ‘You were speeding.’ ‘I was? I didn’t know I was speeding. This is a new car.’ ‘Sir, the car is four years old.’” Police officers know when something doesn’t make sense.

3. Vague sentiments

Specificity is what innocence is made of. When a subject produces vague responses, it may be a sign of guilt or that he’s not being truthful.

Officer: “Sir, what are you doing here in the middle of the night? You’re walking a bit erratically.”
Suspect: “Oh, I’m fine. I’ve got some stuff to do.”
Officer: “Exactly what stuff, sir?”
Suspect: “You know, this and that.”
Officer: “Can you be more specific, sir?”
Suspect: “Why you hassling me?”

4. Use of the word honestly or a similar phrase

Guilty people think that throwing out words such as truthfully and honestly is going to get them off the hook, but those words are often used as a decoy or stall tactic.

Husband: “Did you cheat on me?”
Wife: “Honestly? No.”

Parent: “Did you hit your sister?”
Child: “Okay, Mom, this is the truth…I didn’t do it.”

5. Diverting blame

Kids do this all the time. It’s so much easier to pawn off the guilt or responsibility on some unsuspecting sap.

Parent: “Joey, why did you flunk out of this class?”
Joey: “That class was ridiculous. The teacher was horrible. Ask anyone.”

Employer: “I’m really impressed with your and Jerry’s work, Jim.

The only part that needs work is the second section of the report.”

Employee: “Oh, Jerry mostly handled that section. I agree. It’s not as strong as it could be.”

6. Doth protest too much

If someone starts having a conniption just because you asked a simple question, it can be a tip-off to deception.

Girlfriend: “Tommy, did you make out with Melanie at Cody’s house last night?”
Boyfriend: “What?! Who told you that? That person is a liar! I am going to get to the bottom of this. How dare someone spread these awful lies about me!”

7. Projection

In psychology, a projective test is a type of personality test in which a subject offers responses to ambiguous scenes, words, or images that are shown to him. (The most commonly known type of projective test is the Rorschach Inkblot Test.) The theory behind the test is that when someone is presented with clearly defined questions, his or her conscious mind will answer in clearly defined responses. However, if you present a question or stimulus that is not clear, underlying or unconscious motivations or attitudes take over and can be revealed. In other words, people project their real feelings when they can’t focus on a desired result.

I perform these types of projective tests all the time in my office, and you can do it too. You don’t need official cue cards, inkblots, or the like. Use what you have available to you—paintings on the wall or photos on your desk—as conversation starters. Ask the person to tell you what happens before the picture, what is happening in the picture, and what happens after the picture.

In general, I find that truthful people tell upbeat stories that make sense, while deceptive people tend to be more negative, and their stories lack an ending or don’t make sense. For example:

  • A truthful person might say:
    “Before this picture, a family wanted to sail on this beautiful day.”
    “In this picture, they are sailing, and the waters are calm.”
    “After the picture, they go back home, have a nice barbecue dinner, and drink some wine.”
  • A deceptive person might say:
    “Before this picture…I don’t know…People wanted to move their boat before a storm hits.”
    “In this picture, they are rushing to move the boat to get away from the storm.”
    “After the picture, the boat gets destroyed by the storm anyway.”


Human beings communicate in learned nonverbal patterns—facial expression and body language—that present telling indicators of deception. When people come to my office for a polygraph or an interview, I’m assessing everything they do the second they walk through the door. Are they looking me in the eye? Did they offer to shake my hand? Was their handshake firm? Did they keep their jacket on or take it off? Were they smiling? Were they smiling too much?

Bosses, teachers, parents—they should be doing the same kinds of assessments when conducting an interview or interrogation. They should be looking for that subconscious gesturing or what we call leaking deception, which, as you’ll discover, becomes very obvious once you know what to look for. Of course, you should keep in mind that nothing in investigation is foolproof. Certain facial expressions and body gestures can be the result of mental health and cultural concerns, whether it’s the inability to keep consistent eye contact or a coping mechanism that produces facial tics or foot tapping. That is why it is important to observe an individual both at rest and at stress. If the nonverbal cues begin only at the most crucial or most taxing moments of an interview or interrogation, then that is a pretty good indication of deception. Your best bet is to assess your subject using more than one, or a combination, of the following signs.

1. Fear. Sometimes when I get people hooked up to a polygraph, they look like they’re going to pass out. Although they simply may be nervous, in a general way, about taking a polygraph, that’s usually not a good sign of a person’s innocence. This is known as fear of detection.

2. Eye contact. When it comes to discerning the truth, the eyes usually have it. Deceptive people generally don’t look you in the eye or they break eye contact, particularly at the point of answering a question.

3. Fidgeting. Remember that expression ants in your pants? Well, deceptive people have a whole army of them in their underwear. They can’t sit still or make themselves comfortable.

4. Touching parts of their face or body.

Deceptive people rub their face, their legs. Girls will twirl their hair, also called grooming. If you ask your boss if you can have a raise, and he touches his nose while telling you, “There’s no room for it in the budget,” it may be time to look for a new job. Touching his nose while answering a question means . . . his answer stinks!

5. Fight or flight. Those old caveman instincts have stayed with us over the course of hundreds of thousands of years and seem to turn up at crucial moments of deception—when we feel backed into a corner:

Father: “You stole the money.”
Son: “I did not steal the money. What are you talking about?”
Father: “You did.”
Son: “That’s it. I’m going to my room.”

6. Distance or barriers. As I stated earlier, you never want to interview or interrogate someone across a table or a desk, because that gives him the perception that something is protecting him. And when there’s nothing for a guilty person to hide behind, he will:

  • Try to create distance between the two of you, by leaning back in his chair or physically moving a chair back.
  • Use his body as a barricade to give the illusion of protection, such as folding his arms, or crossing or extending his legs.

7. Charm. Flirting. Flattering. Buttering up the questioner. It’s unbelievable to me that people really do this, but they do. As if telling me they like my hair or my watch is going to make me give them a gold star on their polygraph.

8. Joking. The minute some clown breaks into a story about a priest and a rabbi who walk into a bar, he’s already dug himself into a hole. I’m the only one who should be making bad jokes in my office!

9. Inappropriate reactions. Sometimes during an interview or interrogation—and we get this often on The Steve Wilkos Show—a guest acts weird or in ways that are not congruous with the questions being asked. In the business of credibility assessment, we call this unusual affect.

Questioner: “Did you sexually molest that girl?”
Subject: “Hahaha! I wouldn’t sexually molest a girl. That’s funny.” Questioner: “What do you mean it’s funny?”

When you enjoy something, when you enjoy the power, it will show.


Copyright © 2016 Daniel Ribacoff.

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Daniel Ribacoff is the founder and CEO of International Investigative Group, Ltd. He is a trained polygraph examiner and has been a private investigator for over 23 years. Ribacoff studied at The Academy of Scientific Investigative Training, Philadelphia, PA. He was named as the 1991 Man of the Year for the NYPD Honor Legion. Ribacoff has worked on many notable investigations, including a $120 million dollar bank fraud case for AIG Insurance Co., one of the largest bank fraud cases in US history. He also worked on the 1993 World Trade Center Bombing investigation and conducted investigations into the case US v. Osama Bin Laden, et. al. He has conducted many investigations recovering rare works of art, such as Monet, Picasso, and Twombley paintings. His investigations have resulted in millions of dollars being recovered throughout the world for his clients. He was named as one of the “Top 15” investigators in the US by ION. His firm has been featured in the New York Times, Wall Street Journal, Chicago Tribune, CNN, CNBC, and many others.


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