Following the assassination, Dr. Hopper was sued by all of Hinckley's shooting victims with the exception of Reagan. Brady, Delahanty, and McCarthy alleged that Dr. Hopper had inadequately treated John Hinckley and asked for $14 million dollars damages. They claimed Hopper, as a psychiatric professional, should have recognized that Hinckley was dangerous and put him in a hospital. They further alleged Hopper misdiagnosed Hinckley as having minor problems and rejected his parents' suggestion to institutionalize the younger Hinckley. Finally, they argued Hopper failed to warn police of the reasonable likelihood that Hinckley would attempt a political assassination despite Hinckley's admission that his "mind was on the breaking point."

The suit was later dismissed in the case of Brady v. Hopper, 570 F. Supp. 1333 (D. Colo. 1983), aff'd, 751 F.2d 329 (10th Cir. 1984). The United States District Court held that because Hinckley never threatened anybody, Dr. Hopper could not have known Hinckley was dangerous; or warned Brady and the others of the danger. A majority of Dr. Hopper's sessions were spent discussing Hinckley's obsession with Jodie Foster, but Hinckley did not threaten to harm anyone.

Roger Adelman served as the government's senior prosecutor during the trial of John W. Hinckley, Jr. He served as an assistant U.S. Attorney for eighteen years and then became a partner in the Washington law firm of Kirkpatrick & Lockhart, which specializes in White Collar Criminal Defense. Adelman taught evidence and trial practice at Georgetown University Law Center for a number of years, and participated in a variety of symposiums in the United States and abroad. During his eighteen years with the United States Attorney's office, Adelman tried around two hundred and fifty jury cases, including claims of political corruption, conspiracy, bribery, fraud and murder Although best known for his participation in the Hinckley trial, Adelman was also involved in prosecuting former Representative Richard Kelly in the Abscam political corruption trials.

Vincent Fuller served as senior attorney for the defense in the John Hinckley trial. Hinckley's parents hired Fuller from the Washington D.C. based law firm of Williams and Connolly, a firm known for defending famous people in white collar criminal cases. Fuller's claim to fame came in 1982 when he won an acquittal by reason of insanity for his client, would-be presidential assassin John W. Hinckley, Jr. Since the Hinckley trial, Fuller has defended other noteworthy clients, including boxing promoter Don King and ear-biter Mike Tyson in his trial on charges of rape in 1992. His fee for defending Tyson was $5,000 per day, amounting to a grand total of 5 million dollars. His record is not unblemished, however. Although he successfully defended King against charges of tax fraud, his defense of Tyson resulted in a six-year jail sentence for the boxer. After the Tyson verdict, many critics claimed that Fuller inadequately defended Tyson because he failed to object to a piece of key prosecution evidence.

Dr. Johnson testified as a psychiatric expert for the prosecution of John W. Hinckley, Jr. Currently, she serves as chief of psychiatric services at the Butner Federal Correctional Institute in North Carolina. Dr. Johnson made headlines again in January, 1998, when she evaluated accused Unabomber Theodore Kacynzski. She was summoned after Kacynzski attempted to fire his attorneys and represent himself in the case. Dr. Johnson examined him and ultimately diagnosed him as a paranoid schizophrenic; the trial proceeded and Kacynzski could not represent himself. Earlier in her medical career, she performed a psychiatric evaluation on former televangelist Jim Bakker.

Thomas Delahanty was a Washington D.C. police officer working crowd control at the Washington Hilton on the fateful day of March 30, 1981, when John W. Hinckley, Jr. emerged from the crowd to spray bullets at President Reagan and his entourage. One of Hinckley's bullets struck Delahanty in the neck and ricocheted off his spinal cord. Although he survived the wound, he suffered permanent nerve damage to his left arm. Delahanty was cited for heroism for his valiant effort to protect the President, but was ultimately forced to retire at age 45 from the Washington police force due to his disability. Delahanty lives in suburban Washington.