The US Supreme Court upheld the conviction of Robert Williams for illegal possession of a handgun and heroin found during a "stop and frisk" and a full search incident to his weapons arrest. The Court found that the police officer's actions were in accordance with the standards set in Terry v. Ohio, which allows police officers to approach individuals to investigate possible criminal behavior, even without probable cause for an arrest. If an officer believes that the individual being investigated is armed and dangerous, they may conduct a limited protective search for concealed weapons. In this case, the Supreme Court found that Sgt. Connolly acted justifiably in responding to an informant's tip, which had enough indicia of reliability to justify the officer's forcible stop of Williams.

The dissenting opinion in a case argues that the arrest for illegal possession of a gun was unconstitutional because the police had no authority to frisk the person for a permit. The opinion questions whether a person in possession of narcotics would not have a permit for their gun and suggests that the ease of acquiring pistols is a problem for law enforcement, not the Fourth Amendment. The argument made is that states have the power to enact strict laws governing the purchase and possession of pistols. The author expresses concern about the extension of Terry v. Ohio to "possessory offenses," which they believe is a serious violation of Fourth Amendment protections.

The dissenting opinion in this case questions whether the police had sufficient cause to stop Williams, who voluntarily rolled down his car window. The opinion argues that the combination of Officer Connolly's observation and the tip was not enough justification for the intrusion, as the tip was flawed in several ways. The opinion also expresses concern about extending Terry v. Ohio to possessory offenses and emphasizes the importance of accurate prediction of an unusual event. It suggests that if the state wishes to rely on a tip to validate a stop and frisk, the name of the informer should be revealed or it should be demonstrated that the name is unknown and could not reasonably have been ascertained. The dissenting opinion agrees with Judge Friendly's reasoning that the State did not make a sufficient showing, especially since Connecticut law allows citizens to carry weapons with a permit and does not give police officers special authority to stop citizens for that purpose.

The dissenting opinion in this case argues that the Court's decision expands the concept of warrantless searches beyond what is legitimate and goes against the careful balance that Terry v. Ohio sought to strike between a citizen's right to privacy and the government's responsibility for effective law enforcement. The case involves a police officer who conducted a search of a passenger in a parked car based on unreliable information from an informant. The officer lacked important information, and the frisk was illegal under Terry. The court cannot sustain the arrest and subsequent searches as probable cause is required to justify them.