The following is Part 2 of Crime Story’s coverage of the People vs. Jose Peralta. You can find Part 1 here.

You’re innocent. 

So when a detective accuses you of murdering your neighbor, you agree to take a polygraph test. It doesn’t matter that the officer claims that they have security footage and DNA evidence of your guilt. This is a misunderstanding. It’s a nightmarish who-dunnit that manifested in reality. It should be easy to clear up.

Because you know you’re innocent.

The detective drives you to the polygraph testing facility where you’re sat in a small, stark room. As the examiner explains the test, he hooks you up to the machine. Electronic sensors are placed on your chest and abdomen. A blood pressure cuff is strapped around your bicep. Your middle finger is secured in a plastic clip called a plethysmograph. Then the questions come:

What’s your name?…What’s your birthday?…

Where were you last Wednesday night?

You answer the questions honestly. You keep your breath even and attempt to relax. When the test is over, you sigh in relief. Now it’s time to go home and watch TV and order a pizza.

Then the polygraph examiner pulls up a chair beside you.

He says you failed the test.

And that he knows you’re guilty of murder.


It’s closing arguments in the People vs Jose Peralta and Public Defender Arpa Abrahamian struts in front of the jury box in her maroon kitten heels. Visibly pregnant, but impressively energetic, Abrahamian implores the jurors to see the totality of the circumstances. 

It’s a complex multi-defendant case but here’s the summation: Jose Peralta and his construction coworker, Jose Romero, are charged for the murder of Jose Rodriguez. The prosecution alleges that after Rodriguez accused Peralta’s brother and Romero’s nephew of scratching his truck, Peralta and Romero were so furious that they drove to Rodriguez’s house and lured him outside so they could both stab him to death. The defense argues that the pair never intended for the interaction to become violent — Romero just wanted to make peace with Rodriguez. According to the defense, it was Rodriguez who came out swinging, forcing Romero to stab him in self defense while Peralta watched from the passenger seat of the car. 

The prosecution has two primary pieces of evidence against Peralta. First is the testimony of Rodriguez’s wife, who has given multiple statements with various narratives, some of which include Peralta stabbing her husband and others more vague on the details.

The second major piece of evidence is Peralta’s confession, which occurred after a polygraph test and a lengthy interview with Detective David Ortiz. Part I of this piece detailed the legally permissible ruses and psychological manipulation that Detective Ortiz used during that interview. No one forced Peralta to take the polygraph test and he was never detained, but Ortiz still made the test an attractive option. 

Earlier in the trial the defense played the interview footage for the jurors. When the polygraph was brought up during the interview Peralta shifted in his seat. “How accurate is it?”  

Ortiz gave a reassuring nod. “Almost 100 percent.” 

It was simple, Ortiz explained. If Peralta was telling the truth about his innocence, then the polygraph would clear things up. After the polygraph Peralta could go home. 

Peralta never went home. 

During closing arguments, Peralta stares at a filing cabinet by the clerk’s desk while Abrahamian explains the factors that may have led her client to make a false confession. Peralta was just 18 years old. He had been interviewed for more than 9 hours. And according to several academic assessments, Peralta had an auditory processing disorder, a learning disability that contributed to him being several years behind in math, reading, and basic comprehension. 

Abrahamian argues that Peralta took the test because he genuinely wanted to prove his innocence, but he was taken advantage of by officers who were seeking a conviction rather than the truth.

As Abrahamian plays the recording of Peralta’s confession, Peralta shifts his focus to his shoes.

Video of the polygraph interrogation room blooms on the court TV screen. The footage shows Peralta shaking his head, rocking in his chair and staring at the floor. When polygraph examiner Michael Ward states that he failed the polygraph, Peralta remains adamant that he never stabbed Rodriguez. Ward is undeterred. He questions Peralta with a chummy intimacy. “I got to be honest, man. It’s killing me to see you in this position and I want to help you.” His expressions of sympathy co-mingle with multiple choice questions. “Did you stab him first or last?”…”Did you want to do it or did Vincent force you?” Abrahamian jumps the video forward in time. Over the course of two hours Peralta’s certainty has disintegrated. “I don’t remember stabbing him,” he mumbles. “Maybe I blacked out?” The confession itself comes not with a bang but a whimper. 

Ward asks Peralta “Did you stab him one time or ten?” 

“One,” say Peralta. 

Then he throws up in a waste bin.

The polygraph test in this case presents a logical ouroboros, the details of which are as follows: 

  1. Polygraph examiners are allowed to lie about the subject’s performance. That means it’s possible that Peralta didn’t fail the polygraph at all. 
  2. We will never know if Peralta actually failed the polygraph because while the recording of Peralta’s confession was allowed into evidence, the results of the polygraph itself weren’t admitted in court. 
  3. Polygraphs actually aren’t admissible in most courts because of their frequent false positives. According to the American Psychological Association “there is little evidence that polygraphs can detect lies.” Their findings are based on physiological factors that do not always correlate with a person’s truthfulness.
  4. This means that Detective Ortiz was lying to Peralta when he told him that polygraphs are “almost 100 percent” accurate.
  5. Officers are allowed to lie during interviews and interrogations, meaning that this entire exchange was legal. 

Presented with the supposed infallibility of the polygraph and then confronted with negative results, Peralta may have felt backed into a psychological corner where the only solution was to question his own memory. To be fair, the quagmire of the polygraph doesn’t exclude the possibility that Peralta is guilty. But it does raise substantial questions about the integrity of the process. Enduring the interview and the polygraph would be taxing for anyone. Abrahamian attempts to convince the jury that the circumstances were too much for her client. She states her case plainly.

“An 18-year-old with an intellectual disability was the subject of interrogation for almost 9 hours…He just wanted to go home.”


You’re starting to feel queasy as the polygraph examiner continues his questioning. It’s been hours and you maintain your innocence. You know you’re not a murderer.

But he says there’s security footage of you committing the crime.

And there’s DNA evidence.

And you failed the polygraph test.

And now there’s no question in his mind that you’re guilty.

“This is your chance to tell your story,” he says. “If you don’t say something they’ll think you’re a cold blooded killer.”

It might be at that point that you momentarily think: a false confession sounds like a good idea. And maybe moments turn to minutes and minutes turn to hours.

And then you open your mouth.