TBA Law Blog

Posted by: Russell Fowler on Jul 1, 2017

Journal Issue Date: Jul 2017

Journal Name: July 2017 - Vol. 53, No. 7

To be responsible for a crime, the defendant must traditionally have criminal intent, mens rea, a guilty mind. Hence, the accused cannot be punished for an act perpetrated while insane. Sir Edward Coke observed in 1628: “A madman is only punished by his madness.”[1] And as an 1828 British decision declared, “Insanity vitiates all acts.”[2]

Yet despite the defense’s acceptance in the law,[3] it is controversial.[4] When denying a pardon request, Theodore Roosevelt wrote: “I have scant sympathy with the plea of insanity advanced to save a man from the consequences of crime, when unless that crime had been committed it would have been impossible to persuade any reasonable authority to commit him to an asylum as insane.”[5]

The insanity defense is especially unpopular when it is based on so-called “temporary insanity.” But this was not true in the first case where a plea of temporary insanity was used.[6] The people rejoiced in the streets when the defendant was acquitted.[7]

Daniel Sickles shooting Philip Key

On Sunday, Feb. 27, 1859, at fashionable Lafayette Square, a couple of blocks from the White House, 39-year-old Congressman Daniel E. Sickles of New York, after shouting “You villain, you have defiled my bed and you must die!,”[8] shot and killed the unarmed Philip Barton Key, the son of Francis Scott Key, the author of “The Star Spangled Banner.” The 42-year-old Key was also the district attorney for Washington, D.C., receiving his appointment thanks to Sickles’s influence with his old friend, President James Buchanan.

After doing the deed, Sickles surrendered to the U.S. Attorney General. He was permitted to return to his home on the square, Stockton Mansion, retrieve some personal items, and in the company of the mayor, presented himself at the D.C. jail. The socially prominent Sickles and his beloved dog, Dandy, were given the warden’s comfortable quarters.

Sickles, a cog in the Tammany Hall political machine, rallied help. Three of the best lawyers in America, two from New York City, were assembled for the defense, including the bulldog-like Edwin M. Stanton, who would be Lincoln’s secretary of war. Prosecution was left to the dead Key’s young and inexperienced assistant, Robert Ould. President Buchanan refused to appoint a special prosecutor. So Key’s friends raised funds to hire a leading local lawyer to assist. When the trial convened, there was difficulty empaneling a jury because scores of prospective jurors expressed their support of Sickles’s act of killing his wife’s paramour.

Despite all his advantages, Sickles had problems. Newspapers throughout the country began to expose his “notorious profligacy.”[9] He was notorious for cheating on his wife, the beautiful and much younger Teresa Sickles. As one commentator said, “Sickles is not the man to take the law into his own hands and constitute the avenger of sin.”[10]

The Murder Trial

At trial, the prosecution began by pointing out that Sickles irreverently selected a Sunday to execute his “deed of blood”[11] and that it was “murder, no matter what may be the antecedent provocation.”[12] Testimony described how Key hid behind a tree after the first shot missed and then fell to the pavement when hit by the second. While on the ground, he cried, “Don’t shoot,”[13] but a third shot struck him. Key’s only response was to harmlessly toss his opera glasses at his attacker.

The Sickles Trial

The proof showed that Sickles learned of the betrayal from an anonymous letter and subsequently obtained confirmation from a detective. He then made a hysterical Teresa write a graphic confession admitting that she was “a wicked woman”[14] and detailing at least six liaisons with Key at a house rented for their encounters in a secluded neighborhood. As fate would have it, while Sickles and a friend, Samuel Butterworth, were conversing about the affair in Sickles’s home, they spotted the handsome Philip Barton Key through a window in Lafayette Square as he was slowly twirling his handkerchief in circles, apparently to signal Teresa. Butterworth went outside to detain Key while Sickles hurried upstairs and loaded his pistol.

Defense counsel commenced by countering Ould’s comment about murder on Sunday saying it was Key, “a confirmed, habitual adulterer,”[15] who disrespected the Sabbath. Furthermore, he said Sickles was only acting in self-defense, the defense of his home, his wife, his marriage. Such a husband’s right to vengeance is “given by the law of God.”[16] It was also noted that Key’s adultery was still an offense under the criminal code and the accused was defending himself against that crime. Then defense counsel John Graham raised the defense of temporary insanity saying: “Sickles’ provocation was so enormous that he was, from a legal point of view, insane.”[17]

The defense then attempted to introduce Teresa’s written confession to show Sickles’s state of mind. The elderly judge ruled it inadmissible since it would violate the married couple’s “confidential identity.”[18] Nevertheless, the confession was spread across the nation’s newspapers. Next testimony was given describing Sickles “crying aloud” that morning before the shooting,[19] his upset at seeing Key signaling his wife, and his screams and “unnatural and unearthly sounds” after the shooting.[20] Stanton punctuated the scene by denouncing the prosecution’s “thirst for blood.”[21] Finally, the defense hinted that Key might have been armed, because 12 days before his death Key told a friend, “I am prepared for any emergency.”[22]

The prosecution moved to exclude all evidence of Teresa and Key’s adultery based on relevancy. To the joy of the spectators and the defense (Stanton danced a jig) the judge held that the evidence was admissible as “an explanation.”[23] Thus it became “hard to tell whether Sickles was on trial for murder or Key for adultery.”[24] Another debate ensued when Stanton contended that the burden was on the prosecution to establish that the defendant “was a person of sound memory and discretion at the time the act was committed.”[25] The judge held that every person “is presumed to be sane until the contrary is proved; that is the normal condition of the human race, I hope.”[26]

In rebuttal, the prosecution was not allowed to introduce proof of Sickles’s own adulteries and the proof closed. The judge instructed the jury: “If the jury have [sic] any doubt as to the case, either in reference to the homicide or the question of sanity, Mr. Sickles should be acquitted.”[27] A verdict of not guilty was returned and the cheering crowd unharnessed the horses from a carriage and pulled Sickles triumphantly through the streets of Washington.

Philip Barton Key, the murdered D.C. District AttorneyDaniel Sickles
Teresa Sickles. Although reconciled with her husband,
they were never seen in public again.

The Aftermath

Defense attorneys copied the strategy, increasingly with the support of medical testimony. Yet critics would arise. Mark Twain wrote: “Heaven knows insanity was disreputable enough, long ago; but now the lawyers have got to cutting every gallows rope and picking every prison lock with it.”[28]

As for Dan Sickles, he and Teresa reconciled. She died eight years later. He would go on to serve as a Union general in the Civil War. Some (including himself) said he was critical to winning the Battle of Gettysburg. Others argued his rashness almost lost it for the North. He did lose a leg in the war. President Grant would name him ambassador to Spain. During this appointment he carried on an affair with the deposed Queen of Spain, Isabella II. After being elected to Congress again in the 1890s, he served as chair of the New York Monuments Commission, but was fired for misappropriation of funds.[29] He donated his shattered leg bone for display at the Army Medical Museum and died in New York City at the age of 94 in 1914. He was given a hero’s funeral.


  1. Sir Edward Coke, A Commentary upon Littleton (The first part of the Institutes of the Laws of England), 247b (19th ed. 1832) (1628).
  2. Countess of Portsmouth v. Earl of Portsmouth, 1 Hag. Ecc. 355, 359 (1928).
  3. Various formulas for the insanity defense developed over the years since the influential M’Naghten test was crafted by the House of Lords in 1842. After long adhering to M’Naghten, in Graham v. State, 547 S.W.2d 531 (1977) the Tennessee Supreme Court adopted the Model Penal Code test developed by the American Law Institute (ALI). This was codified in 1995 at Tenn. Code Ann. §39-11-501.
  4. See John Q. La Fond, “Criminal Law Principles,” in The Oxford Guide to American Law 194-95 (Kermit L. Hall ed., 2002).
  5. Theodore Roosevelt, Letter replying to petition for pardon, Aug. 8, 1904, in Works of Theodore Roosevelt 22:425 (Hermann Hagedorn, ed., 1925).
  6. See, e.g., Frank Burd, Generals of Gettysburg 12 (2000).
  7. Thomas J. Fleming, “A Husband’s Revenge,” in Stories of Great Crimes and Trials 71 (1973).
  8. Id. at 62.
  9. Id. at 63 (quoting the New York Evening Post).
  10. Id. (quoting the Diary of George Templeton Strong).
  11. Id. at 64 (quoting Robert Ould).
  12. Id.
  13. Id.
  14. Id. at 66 (quoting Teresa Sickles).
  15. Id. at 65
  16. Id.
  17. Id.
  18. Id. at 67 (quoting Judge Thomas H. Crawford).
  19. Id. (quoting witness Bridget Duffy).
  20. Id. at 69 (quoting witness Robert Walker)
  21. Id. at 67 (quoting Edwin M. Stanton).
  22. Id. at 69.
  23. Id. at 68 (quoting Judge Crawford).
  24. Id.
  25. Id. at 69 (quoting Stanton).
  26. Id. (quoting Judge Crawford).
  27. Id.
  28. Mark Twain, “Unburlesquable Things,” Galaxy Magazine, July 1870, at 137.
  29. See Burd at 13.

Russell Fowler RUSSELL FOWLER is director of litigation and advocacy at Legal Aid of East Tennessee (LAET) and since 1999 has been adjunct professor of political science at the University of Tennessee at Chattanooga. He served as the law clerk to Chancellor C. Neal Small in Memphis and earned his law degree at the University of Memphis in 1987. Fowler has many publications on law and legal history, including many in this Journal.