Park Dietz


Park Elliot Dietz is a forensic psychiatrist who has consulted or testified in many of the highest profile US criminal cases including Joel Rifkin, Arthur Shawcross, Jeffrey Dahmer, The Unabomber, Richard Kuklinski, Betty Broderick, the Beltway sniper attacks, and Jared Lee Loughner.
He came to national prominence in 1982 during his five days of testimony as the prosecution's expert witness in the trial of John Hinckley, Jr., for his attempted assassination of President Reagan on March 30, 1981. Then an assistant professor of psychiatry at Harvard Medical School, Dietz testified that at the time of the shooting, Hinckley knew what he was doing, knew it was wrong, and had the capacity to control his behavior thus was not legally insane.
Dietz is also a criminologist, and in 1987 he created the specialty of workplace violence prevention in founding Threat Assessment Group, Inc., which specializes in analyzing and managing threatening behavior and communications, stalking, risks arising from domestic violence, and other abnormal activity in corporations, colleges, and schools. As of 2013, more than 20,000 senior corporate managers have attended TAG training seminars.
A separate company, Park Dietz & Associates, is a forensic consulting firm specializing in criminal behavior analysis, forensic psychiatry, forensic psychology and other forensic sciences, serving prosecutors, criminal defense attorneys, and attorneys representing defendants and plaintiffs in civil litigation. PD&A's national roster of experts includes physicians, psychologists, and retired FBI agents with wide expertise on the forensic aspects of fields as diverse as neurology, social work and pathology. Both TAG and PD&A are headquartered in Southern California with PD&A having a second office in Washington, D.C.
In addition to his work as a forensic psychologist, Dietz has consulted for television shows including Law & Order and .

Early life and education

Dietz was born on August 13, 1948 and raised in Camp Hill, Pennsylvania, a suburb of Harrisburg. His mother, Marjorie Dietz, who had trained as a nurse and did hospital volunteer work including activities at a local mental institution. His father, Raymond Dietz, was a physician, as was Dietz's grandfather.
Dietz graduated from Camp Hill High School in 1966 and that same year enrolled at Cornell University to major in Psychology and Biology. He was a member of Cornell's Theta Delta Chi fraternity. In 1970 he graduated with an A.B. cum laude in Psychology, and was a Phi Beta Kappa.
In 1970, Dietz received a senatorial scholarship to study at the University of Pittsburgh School of Medicine, transferring in 1972 to Johns Hopkins University. There, he was among a handful of students in the M.D.-Ph.D. Program in Behavioral Sciences funded by the National Institute of General Medical Sciences and the Grant Foundation of New York. From 1972-1975, while completing medical school and course requirements for a Ph.D. in Social Relations, Dietz also earned a Master of Public Health degree.
Dietz worked with the school's noted public health professor Susan Baker on a study of drowning cases and their prevention and epidemiology, using the Haddon Matrix paradigm to categorize specific prevention measures for specific injuries. In 2012, Baker wrote that Dietz, "later applied the Matrix to the problem of rape, showing its value in formulating approaches to intentional injury…and the Haddon Matrix probably played a role in his development of an entire industry addressed to workplace violence prevention."

Early career

After completing his residency in psychiatry at Johns Hopkins in 1978, Dietz began teaching at Harvard Medical School, where at age 29 he was the school's youngest assistant professor. While teaching at Harvard, Dietz also was the director of forensic psychiatry at Bridgewater State Hospital, a facility for the criminally insane in Bridgewater, Massachusetts.
After four years at Harvard, Dietz became an associate professor at the University of Virginia in 1982, teaching law, behavioral medicine and psychiatry at the UVA School of Law while also being the medical director at UVA's Institute of Law, Psychiatry and Public Policy. He taught on the Charlottesville campus for six years, and was promoted to Professor of Law in the School of Law and Professor of Behavioral Medicine and Psychiatry in the School of Medicine.

The John Hinckley, Jr., Trial

attempted to assassinate President Reagan outside Washington, D.C.'s Hilton Hotel on March 30, 1981, and Hinckley's 1982 trial included Dietz as an expert prosecution witness. In his five days of testimony, Dietz told the jury that Hinckley told him that he felt shooting the president accomplished his goal of trying to impress actress Jodie Foster. Dietz quoted Hinckley as saying, " 'Actually, I should feel good because I accomplished everything on a grand scale… I did it for her sake…' "
Assistant U.S. Attorney Roger Adelman, the chief prosecutor, argued that Hinckley may have been emotionally unstable at the time of the shooting, but that he was not so mentally disturbed that he could not understand what he did when he shot Reagan. Dietz and the colleagues whom he led wrote the prosecution's 628-page report on Hinckley's mental state.
Dietz diagnosed Hinckley with personality disorders: narcissistic, schizoid, and a mixed personality disorder with passive-aggressive and borderline traits, plus persistent sadness. Hinckley had, according to the Dietz-authored report, "a pattern of unstable relationships; an identity disturbance… chronic feelings of emptiness and boredom…inability to sustain consistent work behavior…lack of self-confidence." But Dietz also told the jury that none of these personality issues free Hinckley from legal responsibility for shooting Reagan. "On March 30, 1981, Mr. Hinckley, as a result of mental disease or defect, did not lack substantial capacity to appreciate the wrongfulness of his conduct."
Dietz used Hinckley's assessment of the assassination location, as Reagan walked outside the Hilton Hotel, as an example of how Hinckley did, "appreciate the wrongfulness," of his actions, but nonetheless went forward. Dietz said Hinckley had a, "long-standing interest in fame and assassination," and that he had studied, "the publicity associated with various crimes."
Hinckley's mental health state was clear enough that he knew the type of bullet that would do the most damage, Dietz told the jury, plus the step-by-step movements needed to get close to Reagan on March 30. "He was able to make other decisions on that date," Dietz said. "He decided where to go for breakfast, what to eat…He made personal decisions of that sort….He deliberated and made a decision to survey the scene at the Hilton Hotel. There was no voice commanding him to do that…He decided, as he tells us, to go to the Hilton to check out the scene to see how close he could get." He also explained that Hinckley summarized, "…the situation as having poor security…He saw that the range was close and within the distance with which he was accurate, and at the precise moment that he chose to draw his revolver there was a diversion of attention from him…The Secret Service and others in the presidential entourage looked the other way just as he was pulling the gun…Finally, his decision to fire, thinking that others had seen him…indicates his awareness that others seeing him was significant because others recognized that what he was doing and about to do were wrong."
Hinckley's defense team argued that he was schizophrenic and thus not criminally responsible for his actions. After eight weeks of testimony, the jury on June 21, 1982 found Hinckley not guilty on all 13 counts by reason of insanity, a verdict that so shocked the nation that Senator Arlen Specter held a hearing of the Senate Judiciary Committee to question the jurors and both the American Psychiatric Association and American Bar Association appointed task forces to work on a revised test of insanity to clarify federal law.
The trial catapulted Dietz into the national spotlight: attorneys took special note of his unique knowledge of deviant behavior, with the FBI also seeking his expertise. His concurrent teaching at the University of Virginia from 1982 to 1988 ended with Dietz moving to Southern California to start his forensic consulting firm.

Jeffrey Dahmer

Serial killer Jeffrey Dahmer murdered 17 boys and men from 1978 to 1991, all but one of them in Milwaukee, Wisconsin. Dietz was hired by the prosecution to evaluate Dahmer's claim that he was "guilty but insane." Dietz interviewed him for 18 hours, with the psychiatrist describing Dahmer as, "articulate, rational and motivated to speak the truth." During his two days of testimony, Dietz explained to the jury that Dahmer was not insane or driven to commit murder but, instead, had sexual disorders and exhibited sexually deviant behavior with his victims, but purposely drank himself to the point of intoxication when he killed. Dahmer, he said, also kept the skulls of 11 of his victims: far from being insane, Dietz said Dahmer, calmly and rationally, knew that keeping, "some of his favorite items, these keepsakes, a very big risk of being detected for all these serious crimes."
Dietz was impressed at how Dahmer remembered intricate details of each murder. The two men watched some of Dahmer's cinematic favorites including , The Exorcist III, plus gay pornography.
Dahmer also gave Dietz plans for a temple he wanted to build for most of the 11 victims' skulls that he kept, with plans to paint them. "Mr. Dahmer drew for me a diagram of what he had in mind—planned for the temple," Dietz told the jury. "And that diagram of the temple shows 10 skulls on a table, with incense burning on both ends, and two whole skeletons on either end of the black table…and a special globe lamp to impart an eerie sense of lighting. And he wanted a black leather chair so that he could sit in the leather chair and admire his collection. If he did this, and had it set up this way, he…could somehow get in touch with some spiritual force or power."
Both the Star Wars and Exorcist films had evil characters that inspired the temple, specifically the emperor in Return of the Jedi and the devil in The Exorcist III. "He identified with the characters," Dietz told the jury, "because he felt that he was thoroughly evil and corrupt."
At the conclusion of his 1992 trial, Dahmer was convicted of the 15 Wisconsin murders to which he had confessed, and received 15 life sentences.

The Unabomber

The "Unabomber" terrorist Ted Kaczynski injured 23 people and killed three more using homemade bombs from 1978 to 1995. Kaczynski pleaded guilty to all federal charges including murder just after his 1998 trial began: though Dietz was unable to interview him before that for federal prosecutors, the psychiatrist did read his journals, interviewed those who knew him, and reviewed all of the evidence gathered by investigators. Kaczynski's writings, he said in an interview with The New Yorker magazine, "scream geek, not schizophrenic," contrary to the defense team's psychiatric evaluation of Kaczynski as a paranoid schizophrenic. "They're full of strong emotions, considerable anger, and an elaborate, closely reasoned system of belief about the adverse impact of technology on society," Dietz said. "The question always is: Is that belief system philosophy or is it delusion? The answer has more to do with the ideology of the psychiatrist than with anything else."

Andrea Yates

Dietz attracted considerable controversy following his testimony in the 2002 trial of Andrea Yates, a woman convicted of drowning her five children in a bathtub. Dietz was the prosecution's lone mental health expert, and testified that shortly before Yates committed the crime, the television crime drama franchise Law & Order had aired an episode about a woman who drowned her children and was found innocent by reason of insanity. No such Law & Order episode existed, and when the error became known, Yates' murder conviction was overturned by an appeals court. The negative publicity following the Yates trial led Dietz to be dropped as an expert from Marcus Wesson's murder trial.

The Meese Commission

Dietz was one of 12 people appointed in 1985 to President Reagan's Attorney General's Commission on Pornography, better known as The Meese Commission after then-U.S. Attorney General Edwin Meese. The commission's final, 1,960-page, five-part, 35-chapter, report was published in July 1986. At the University of Virginia law school library's special collection department, the inventory of Dietz's papers includes 16 boxes dedicated solely to his work on the commission, covering a broad range of sexuality issues from nude sunbathing to bondage publications and Playboy magazine cartoons plus one box bearing a title with the now-antiquated phrase, "Dial-a-Porn."
In his personal statement in the commission's report, Dietz contrasted his commission work with his many years of studying the psychopathic behavior of killers, writing that when he joined the commission, "…the morality of pornography was the farthest thing from my mind... Thus, I was astonished to find that by the final meeting of the Commission, pornography had become a matter of moral concern to me. While other Commissioners may have learned things about the dark side of life that they had never known, I remembered something about the higher purposes of life and of humanity's aspirations that I had forgotten during too many years working on the dark side."
Dietz also stated in the final report, "In my opinion, we know enough now to be confident in asserting that a population exposed to violent pornography is a population that commits more acts of sexual brutality than it otherwise would and to suggest somewhat less confidently that the same is probably true of a population exposed to degrading pornography."

Meese Commission's 8-Point "Medical and Public Health" Problems Involving Pornography

Dietz's extensive commission statement outlined eight areas in which pornography creates, or helps foster, "a medical and public health problem." Surveying these issues, Dietz wrote, in part:
Dietz also wrote that pornography is, "both causal and symptomatic of immorality and corruption. A world in which pornography were neither desired nor produced would be a better world, but it is not within the power of government or even of a majority of citizens to create such a world…a great deal of contemporary pornography constitutes an offense against human dignity and decency that should be shunned by the citizens, not because the evils of the world will thereby be eliminated, but because conscience demands it."