However, knowledge that a subject is armed has successfully been used in the past as a component of reasonable suspicion.
Thompson v. United States: There is Nothing Wrong with Carrying a Rifle for Protection
The Gourko decision was announced in April of 1894, [FN98] and the Starr case in May of that same year. [FN99] Seven months later, in Thompson v. United States, [FN100] the Supreme Court again emphasized its determination not to let Judge Parker draw adverse inferences about an individual because of his exercising the right to bear arms.
Thomas Thompson was a seventeen-year-old farmboy. [FN101] Half a mile away lived Charles Hermes, who made threats to kill Thompson if he came near the Hermes farm. [FN102] One afternoon, Thompson was sent to deliver a bundle to a woman who lived a few miles away. [FN103] The only road to the woman's house went by the Hermes farm. [FN104] Passing by the farm, Thompson got into a heated argument with Hermes, who repeated his threats to kill Thompson. [FN105] After delivering the bundle, Thompson, realizing that the only road home was the road that ran by the Hermes property, borrowed a Winchester rifle. [FN106]
*304 As Thompson rode home, Hermes's sons called out to Thompson. [FN107] One of the sons, Charles Hermes, started towards a gun that was propped on a fence. [FN108] Thompson, believing that Hermes intended to kill him, shot Hermes first, and then fled on horseback. [FN109] Charged with murder, Thompson pleaded self-defense. [FN110]
In the Thompson trial, Judge Parker instructed the jury that they were free to conclude that Thompson had provoked the trouble, and therefore lost his right to self-defense. [FN111] According to Judge Parker, Thompson could be viewed as the instigator of the confrontation because he had armed himself and returned to a place where he knew Hermes would be. [FN112] Similarly, the judge instructed the jurors to the effect that they should not convict Thompson of manslaughter, rather than murder. [FN113] By arming himself, Thompson had shown the kind of deliberation and premeditation which amounts to murder. [FN114]
Quoting at length from the Gourko case, the Supreme Court unanimously reversed Thompson's conviction because of the defective jury instructions. [FN115] Merely being armed and traveling by the only road available could not possibly be considered evidence that Thompson wanted to provoke trouble or that he intended to kill Hermes. [FN116]
The Court concluded that the trial court's error "is in the assumption that the act of the defendant in arming himself showed a purpose to kill formed before the actual affray." [FN117] That same error was found in the instructions regarding the right of self-defense in Gourko. [FN118] Thompson was freed, and was not retried. [FN119]
The Court's unanimous opinion was written by Justice George Shiras, Jr. [FN120] The next year, Justice Shiras joined a dissent which highlighted his concerns about the abusive power of judges - concerns which had perhaps been exacerbated by the cases coming from Arkansas. In Sparf v. United States, [FN121] the Court considered another set of abusive jury instructions. The majority of the Court held that juries do not need to be told that they have a legal right to vote their conscience in order to acquit a defendant who is technically guilty. [FN122] Justice Horace Gray dissented with Justice Shiras *305 joining. [FN123] The Gray dissent observed: " ut, as the experience of history shows, it cannot be assumed that judges will always be just and impartial...." [FN124] In a comment certainly reflective of the Court's view of Judge Parker, Gray and Shiras noted that many judges "occupied in the administration of criminal justice are apt, not only to grow severe in their sentences, but to decide questions of law too unfavorably to the accused." [FN125]
In support of juries being told about their right to vote their conscience, Gray and Shiras affirmed the right of armed resistance to abusive government and extolled the jury as an institution that could prevent the need for armed resistance. [FN126] Gray and Shiras quoted Theophilus Parsons, whom they described as "a leading supporter of the constitution of the United States in the convention of 1788, by which Massachusetts ratified the constitution, appointed by President Adams, in 1801, attorney general of the United States, but declining that office, and becoming chief justice of Massachusetts in 1806." [FN127] Arguing in favor of the proposed federal Constitution, Parsons had explained that jury rights would prevent the people from having to use force against a potentially oppressive federal government:
'The people themselves have it in their power effectually to resist usurpation, without being driven to an appeal to arms. An act of usurpation is not obligatory; it is not law; and any man may be justified in his resistance. Let him be considered as a criminal by the general government; yet only his fellow-citizens can convict him. They are his jury, and, if they pronounce him innocent, not all the powers of congress can hurt him; and innocent they certainly will pronounce him if the supposed law he resisted was an act of usurpation.' [FN128]
As Justice Shiras understood, restraints on trial judges - whether the restraints are imposed by appellate courts or by juries - are not contrary to law and order. Indeed, such restrictions help assure the peaceful continuation of constitutional government by protecting the fairness of criminal trials.
http://www.davidkopel.org/2A/LawRev/Self-Defense-Cases.htm
One can reasonably conclude from this decision that no, being armed is not justification for police harrassment.