Thomas Perez Jr. first felt anxious that something bad might have happened to his father, Papa Tom, on an August night in 2018.

Papa Tom — people called Thomas Perez Sr. that — had put their family dog, Margosha, on her leash for a quick walk to the mailbox in their Fontana neighborhood, though it was nearly 10 p.m. But now, here was Margo back alone, the leash hanging off her collar, and Papa Tom nowhere to be found. Not at the mailbox, not at the neighbors, not at the nearby park.

Though he was elderly and spoke limited English, Papa Tom was a bit of a romantic player, and a secretive one at that. At first, Perez thought maybe his dad had met up with a lady friend. But by the next day when there was still no word, Perez was worried enough to call the Fontana Police Department and report the septuagenarian as missing.

That simple call for help would leave Perez a broken man. By the end of the week, under intense pressure from police detectives, he had falsely confessed to killing his father and was locked inside a psychiatric ward — though Papa Tom was alive and unharmed.

The cause of his false confession, Perez claimed in a lawsuit that he recently settled with the city for $900,000, was a coercive interrogation by detectives that lasted more than 17 hours.

Detectives told Perez that they had his father’s dead body and hard evidence that Perez had killed him. They said there was blood all over the house the two men shared. They told him that blood was even on Margo’s paws, and that Margo had been traumatized by what he had done. In court documents and videos of the interrogation, police repeat these accusations again and again. They also searched his house, persuaded him to let them take naked photos to document non-existent injuries he might have sustained from the struggle with his father, fed him suggestions on how the alleged crime had taken place and said they were sending Margo to be euthanized.

And the department considered every one of those interrogation tactics reasonable.

“I start to absorb this false belief that they put together, and I’m accepting it as a truth,” Perez said years later in a deposition about what happened to his mental state during that interrogation. “I just allowed the belief of others to dominate me.”

What happened to Perez is an extreme example of how a police interrogation method in common use in the U.S. can lead suspects to make false statements — and even falsely confess to crimes they did not commit. Across California and the U.S., detectives are trained to lie. They regularly use falsehoods to illicit confessions, sometimes refusing to even consider alternatives to a suspect’s guilt.

That, said El Dorado County Dist. Atty. Vern Pierson, is a problem because lying by police can lead to “very bad results.”

Pierson is working to change how police conduct interrogations. He advocates that California require police to be trained in newer methods and no longer allow detectives to lie to suspects to trick them into confessions.

“The Fontana case is an extreme one, but it fundamentally begins with a mistaken belief about the use of deception in the interview room,” Pierson said. “A community caretaker doesn’t lie or deceive the community it serves, at least not for very long, without the community questioning, ‘Are you really my caretaker or something else?’”

Fontana officials said they were unable to respond to questions from The Times by a Friday deadline. But on Wednesday the city posted a statement on its website saying the settlement was “a business decision” designed to “save the City further time, effort, and expense.”

The city said it “vigorously” denied any suggestion that its officers had broken state or federal laws. “Had Mr. Perez requested an admission of wrongdoing, the case would never have settled,” the statement said.

Officers had good reason, the statement said, to suspect Perez. A cadaver dog indicated the presence of human remains in the Perez house. Moreover, police claimed, Perez had thrown out clothing belonging to his father, as well as bedding and a shower curtain.

The statement also disputed that the interrogation was unduly harsh. “Mr. Perez was not isolated in an interview room for 17 hours,” the statement said. In fact, he was “fed multiple times and was taken to a local coffee shop where he was able to freely walk into the location without an escort to provide an interview break.”

But a more detailed review of exactly how detectives investigated and interrogated Perez, based on depositions taken for Perez’s lawsuit and excerpts from the detective’s interrogation sessions, raises disturbing questions about what happened to him — and the risks facing anyone suspected of a crime.

On the afternoon of Aug. 8, 2018 — about 16 hours after his dad had walked off for the mail and not returned — Perez called Fontana police to report his father missing.

The officer who took the call later told her supervisor the exchange made her suspicious: Perez seemed distracted, and not overly concerned for his father’s welfare.

Police decided to go to Perez’s house to talk to him in person. At least three officers eventually showed up, and one asked if Perez would come down to the station to talk to detectives while other officers searched his house.

Perez didn’t know it quite yet, but he was now a murder suspect.

They put him in an interrogation room, and detectives took turns grilling him.

“I start to absorb this false belief that they put together, and I’m accepting it as a truth,” Thomas Perez Jr. said of his mental state during the Fontana police interrogation.

(Fontana Police Department via Law Office of Jerry L. Steering)

When detectives first suggested he might have killed his father, Perez reacted with disbelief.

“I’m shocked. I’m upset. I can’t understand. I’m at loss for words,” he recounted in a 2022 deposition. “I kept telling them they’re nuts.”

The officers didn’t listen.

They kept interrogating him — all night long. The next morning, they put him in a car, and while continuing to tell him they believed he had killed his father, drove him to various locations in Fontana where they claimed he might have committed the crime. They brushed aside Perez’s denials and his pleas for medications he took for anxiety and depression.

One detective even suggested that, while under the influence of this medication, he had killed his beloved father.

“That medication you’re taking has caused you — Thomas — to have some issues,” the detective said, according to a transcript contained in court documents. “Where can you take us to show us where Daddy is? … The medication, it took over, and we need to find Daddy right now.”

When Perez failed to lead them to his father’s dead body, police took him back to the department, ignoring his requests to be taken to a hospital because he felt ill. From that point on, the interrogation grew worse, according to Perez’s lawsuit.

Detectives told Perez they knew his father was dead and had evidence Perez had done it. At one point, they brought Margo into the interrogation room. Surely he could see how traumatized the dog was at having watched him kill his father, they told him. The dog would not recover psychologically, they said, and would have to be euthanized.

They told Perez to say goodbye to her.

As part of their interrogation, Fontana police told Thomas Perez Jr. his dog had seen him kill his father — a slaying that never occurred — and would have to be euthanized.

(Fontana Police Department via Law Office of Jerry L. Steering)

They even summoned a family friend to the station, told him they had rock solid evidence Perez had done it, and tried to get the friend, Carl Peraza, to elicit a confession.

In a deposition submitted for Perez’s lawsuit, Peraza recounted that at first he couldn’t believe Perez could have killed his father. He knew the men to have a loving relationship, and had never seen any indication that Perez was violent toward him. But police told him they had overwhelming evidence of Perez’s guilt.

Peraza was allowed into the interrogation room without police, who were monitoring from a hidden recording device.

“I wanted to talk to Tom to tell him that he’s in very, very big trouble; that he has to recall if — if he forgot, or whatever, that he has to recall what happened to his father because he’s being charged with murder,” Peraza said in the deposition.

But when Peraza left the interrogation room without that confession, he learned something stunning: Police had duped him as well. Standing in the hall of the station, Peraza recounted, an officer admitted that they did not, in fact, have proof of his guilt.

“It went from overwhelming to circumstantial,” Peraza said. “And so I wanted to go in and let Tom know, after I just drove him, you know, to try to confess, that it was circumstantial, not overwhelming, like I was told.”

But police would not allow Peraza back inside.

Exhausted, deprived of his medications and confused by the barrage from detectives who took turns berating him, Perez’s mental state began to deteriorate.

“I had been able to hold my own and, you know, go back at them and what have you,” Perez recalled in a 2022 deposition. “But now they’re reassuring me that my father is dead and that I don’t remember, and because of my medications, I blanked it. And they’ve been trying to help me, and they recovered a body already … And then I start losing it.”

Perez began to agree with the officers. Yes, he said, he had killed his dad. Maybe they had fought and he had punched him in the face. Maybe he had stabbed him with scissors in the belly. Maybe he had rolled the body inside a shower curtain, as the detectives suggested.

Then, left alone in the interrogation room with the growing belief that he had harmed his father, he took the leather lace off his shoe, made a slipknot and attempted to hang himself on the desk.

But the lace broke.

While Perez was attempting to end his life, Fontana police were busy building a case for a crime that never happened.

They set up a command post in an RV in front of the Perez house and set to dismantling it in search of evidence. They sliced open a leather sofa, according to court documents. They moved a hot tub, damaging the motor. The contents of drawers and closets were pulled out.

They brought in what police would describe in a search warrant application as a K-9 cadaver dog that allegedly picked up a scent in an upstairs hallway. However, the dog was not an official police canine, and instead belonged to a sheriff’s department volunteer.

Police also used a liquid known as Bluestar that is meant to be a first-line method of picking up blood stains not visible to the human eye. It is known to give false positives for other substances, including food fibers and minerals found in household goods such as paint. (The Perez house was under construction.) Police claimed that Bluestar conclusively found large amounts of blood, but that evidence was never confirmed by a lab and no officer would later testify to seeing any visible blood.

Then, about 30 hours after Perez reported his father missing, police solved the case.

On Aug. 9 at about 8:45 p.m., police spoke with Papa Tom’s daughter in Northern California, who told them he was fine. He had indeed gone to visit a friend two evenings prior without telling Perez, she said. He went to Los Angeles International Airport the next day to catch a flight to Oakland to visit his daughter. He was at the airport as they were speaking, she told police.

Fontana police were dispatched to LAX to confirm the story. For unclear reasons, they detained Papa Tom and read him his rights before bringing him back to Fontana.

But Perez’s nightmare was not over.

About two hours after police confirmed Papa Tom was alive, they recommended that Perez be committed to a psychiatric ward for what is known as a “5150” hold, which can last up to three days. Perez said in court documents that police told staff at the hospital that he was not allowed to receive phone calls. Until he was released days later, Perez did not know his father was alive.

Peraza picked him up from the hospital, and took him home to Papa Tom. Margo had been retrieved from the shelter where police had sent her — saved from death by her microchip that proved she wasn’t a stray but with a leg injury that would require surgery. The trauma was still fresh for them all.

“It was difficult to talk about anything, it was difficult to hold back, but you didn’t know what to do or say,” Peraza said in court documents.

Perez declined to be interviewed for this article through his lawyer, Jerry Steering. Peraza did not return a call or text.

But Peraza said in court documents that his friend has never fully recovered.

“There’s a sadness there, that I can tell by the way he acts, even sometimes the way he walks or stands,” Peraza said. “He’s not the same.”

And still, the police were not done with Perez.

Six days after Perez made his initial call to police — and four days after Papa Tom was located — police obtained yet another search warrant, this one to place a GPS device on Perez’s car. Police, “without explanation or any facts, now suggested to the court that some third unknown party may have been the victim of a homicide,” an expert witness hired by Perez wrote in court documents.

That witness, Jeffrey Noble, is a former deputy police chief with more than 30 years of experience. “No reasonably well-trained police officer would have believed that they had probable cause to obtain a search warrant in these circumstances,” Noble wrote.

Despite their ongoing attempts to locate a victim or a crime, police found no evidence and eventually abandoned their efforts. Perez decided to file a lawsuit.

Bringing such claims against police is difficult. Police officers in the U.S. enjoy qualified immunity that protects them from lawsuits involving much of what they do in the scope of their jobs. When Perez filed his suit, Fontana argued that the case should not go forward because the officers had qualified immunity.

In depositions, the detectives who had hounded Perez nearly to death claimed that they were only following their training.

“We had been with Mr. Perez all day and we were running out of things to say to him to try to get the answer,” one of the detectives explained. “We used a ruse to elicit certain information and that is perfectly legal under the law and it is perfectly legal under the policies and procedures of the Fontana Police Department.”

In June 2023, U.S. District Court Judge Dolly M. Gee, after reviewing hours of interrogation tapes, sided with the police on some of the issues. She ruled in favor of the officers when it came to Perez’s claims that police had unlawfully searched his home and used excessive force. But she declined to toss several of the claims stemming from Perez’s allegations that officers had falsely imprisoned him and inflicted emotional distress. A jury, she ruled, would get to review the evidence and decide whether Perez had been treated fairly. After that ruling, Fontana officials entered settlement talks.

Even years later, during a deposition in 2022, Perez struggled to explain what happened to him in that interrogation room, and how officers could have persuaded him to confess to killing his father.

“I never want to be in that kind of place again mentally,” Perez said. “I didn’t know anybody could be in that kind of place. I didn’t know such a place exists.”