Michael Hicks walked into an Allentown convenience store at 3 a.m. on a summer morning in 2014. He had a handgun in his waistband and a license to carry a concealed weapon. That didn't prevent the police from stopping Hicks' vehicle before he left the parking lot.

Things got worse for Hicks. Once confronted by the police the officer smelled alcohol and found marijuana in his pocket.

How did Hicks, lawfully carrying a firearm, end up arrested for DUI and possession of marijuana?

The police relied on a 50-year-old landmark U.S. Supreme Court decision and a 1991 ruling from the Pennsylvania Superior Court.

Prior to Terry v. Ohio, 392 U.S. 1 (1968) the concept of an investigatory stop was pretty straightforward. A police officer could act on a hunch and attempt to voluntarily engage an individual. However, once that encounter became involuntary the suspect was considered seized and the police needed probable cause to detain the suspect.

That all changed after Terry. The Supreme Court created a degree of suspicion somewhere between a hunch and probable cause—now known as reasonable suspicion. The Supreme Court authorized police officers lacking probable cause for an arrest to conduct a frisk for weapons if the officer believed the individual was dangerous.

On Halloween in 1963, a veteran Cleveland detective saw two men standing on a downtown street acting in a way that seemed suspicious to the detective. The detective observed the two men, one of whom was John Terry, take turns walking back and forth, in front of a store window. After each trip the two men would talk. The detective recalled that the men repeated this ritual at least a half dozen times. A third man came along as the two men spoke.

The detective approached the three, suspecting they were planning to rob the store. He identified himself as a police officer, and asked their names. Unsatisfied with the responses, the detective spun Terry around, patted down the outside of his clothing, and felt a pistol in his overcoat pocket.

Terry and another man were subsequently charged with carrying a concealed weapon and both filed a motion to suppress the guns as the fruits of an unlawful search.

The Supreme Court found that the detective “seized” Terry and subjected him to a “search” within the meaning of the Fourth Amendment. But the Fourth Amendment protects against unreasonable searches and seizures, so the court next had to determine whether Terry's seizure and search were “reasonable.”

The events the detective witnessed made it reasonable for him to believe that either Terry or his companions were armed. “The record evidences the tempered act of a policeman who in the course of an investigation had to make a quick decision as to how to protect himself and others from possible danger, and took limited steps to do so.”

The court found that the search was reasonable, and concluded that the gun found on Terry was properly admitted into evidence.

Over time the reasonable suspicion standard from Terry evolved from an investigatory tool to a crime-fighting tool through the advent of “stop and frisk.”

In the early 1980s, if a police officer had reasonable suspicion of a possible crime, she had the authority to stop an individual and ask questions. Reasonable suspicion could be established by a neighborhood's crime rate or even the time of day or night. For her safety, and the safety of others, the officer could pat-down the individual—if a gun was found the inquiry could continue or an arrest, based on probable cause, could ensue.

If, based on the subject's answers, the suspicion level did not escalate to probable cause for an arrest the person would be released immediately.

Stop and frisk became popular in New York City. Opponents of stop and frisk argued that the police stops were discriminatory because they did not reflect the city's overall census numbers.

Supporters argued there were 2,245 murders in New York City in 1990. By 2012, the number had dropped to 414, the lowest since police began keeping records.

Finally, in 2012, U.S. District Judge Shira Scheindlin put a stop to it. She called the city's stop-and-frisk tactics “indirect racial profiling.” The police used the tactic more than 4.4 million times between 2004 and 2012. The vast majority of the stops were of African Americans, 52%, and Hispanics, 31%. And 88% of stops resulted in no further law enforcement action.

Stop and frisk is not unconstitutional. There is no question that Pennsylvania law provides that an individual may be stopped, briefly detained and frisked for investigatory purposes if the police observe unusual and suspicious conduct on the part of the individual seized.

That brings us closer to Hicks' dilemma.

In 1989, Charles Robinson Sr., was observed by a Pittsburgh police officer bending over into a van with a gun sticking out of the back of his pants.

Because of the presence of children in the area, the officer decided to confer with her partner. The officers returned and stopped Robinson's van.

After Robinson stepped out of the van, the officer informed him that she had seen a gun in the back of his pants. She performed a quick pat down of Robinson and discovered a holster inside the back of his shorts.

The officer then looked into the van and saw a gun on the floor beside the driver's side seat with deep scratches through the serial number.

In Commonwealth v. Robinson, 600 A.2d 957 (1991) the Pennsylvania Superior Court found that possession of a concealed firearm by an individual in public is sufficient to create a reasonable suspicion that the individual may be dangerous. The court found that the observation of a weapon in and of itself was enough to trigger reasonable suspicion—and permit a police officer to temporarily detain that individual.

In Commonwealth v. Hicks, No. 56 MAP 2017, decided May 31, the Pennsylvania Supreme Court overturned Robinson, a 28-year-old precedent.

Hicks was armed and had a license to carry a concealed weapon. Pennsylvania Supreme Court Justice David Wecht writing for the majority contends, “A police officer in the field naturally relies upon his or her common sense when assessing criminal activity. When many people are licensed to do something, and violate no law by doing that thing, common sense dictates that the police officer cannot assume that any given person doing it is breaking the law. Absent some other circumstances giving rise to a suspicion of criminality, a seizure upon that basis alone is unreasonable.”

In overturning Robinson the Pennsylvania Supreme Court said evidence from Hicks' detention should have been suppressed. Wecht wrote, Robinson “contravenes the requirements of the Terry doctrine and thus subverts the fundamental protections of the Fourth Amendment.”   Wecht concludes, “The Superior Court patently has erred in concluding that the 'possession of a concealed firearm by an individual in public is sufficient to create a reasonable suspicion that the individual may be dangerous.'”

Some people are barred from gun ownership, and a license is required for a concealed firearm, the court said. But “there is no way to ascertain an individual's licensing status, or status as a prohibited person, merely by his outward appearance.”

Matthew T. Mangino is of counsel with Luxenberg, Garbett, Kelly & George/ His book “The Executioner's Toll, 2010″ was released by McFarland Publishing. You can reach him at www.mattmangino.com and follow him on Twitter @MatthewTMangino.