Police first encountered the man walking the streets of Abington with an AR-15 rifle slung across his back around 8:30 p.m. Friday.

In talking with officers that night, he gave only his first name and explained that he "wanted to educate the public about his right to carry this weapon," Abington Township Police Chief Patrick Molloy said. "He also wanted to gauge the political climate of Abington Township."

When that same man resurfaced Monday afternoon, carrying the same type of semiautomatic weapon through the North Hills, Ardsley, Glenside, and Abington Shopping Center sections of the township, residents became alarmed. Sightings prompted at least a dozen 911 calls, Molloy said, and ignited online debate about the balance of citizens' Second Amendment rights and public safety. Pennsylvania is one of 45 states that allows citizens to openly carry firearms in public places.

In an open letter to residents, Molloy called the man's action a "passive-aggressive tactic" aimed at drawing law enforcement officers into a debate over the Second Amendment. During multiple conversations with officers, the man with the AR-15 appeared to be recording the encounters on his cellphone, Molloy said. On YouTube, open-carry advocates across the country have posted thousands of videos documenting their interactions with police.

"We believe we know who he is," Molloy said. "We believe he does not pose a threat given our contact with him."

Molloy would not name the man but said police believe he lives in the township.

The man's route Monday seemed to be about three to four miles long. He walked through neighborhoods and by schools, Molloy said, but never onto private property. He also did not walk on sidewalks adjacent to school buildings, Molloy said, and kept his gun slung and pointed down at all times.

Molloy said the man had not broken any laws.

"The clear line would be if he were to carry that weapon onto private property where the owners or those in authority have a rule in place where you cannot carry a weapon on property," Molloy said. "The other one, where we operate very often in the gray, is if he were to unsling that weapon and we or the community would interpret that as a threat. We would have to evaluate that."

Molloy said there was no indication that the man — with whom local authorities had had no contact before Friday — would use the weapon to hurt anyone. Still, the chief urged people not to provoke or confront the man, or even speak with him. If citizens feel threatened, they should call 911, Molloy said.

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On social media, reactions were swift and impassioned. Many came to the man's defense. "Isn't PA an open carry state?" one Facebook user asked in a comment on the Police Department's post.

"He has a right to carry it," another person wrote. "Now if he decides to point it in the wrong direction where it could be considered a threat to human life … shame on him."

Other opinions were more critical.

"[T] his is the type of idiot who will help us lose our second amendment rights," wrote one Facebook commenter.

Laura Miller, 59, of Glenside, said she was in disbelief when she first heard what was happening.

"It's unfortunate this individual chose this way to try and make his point," Miller said. "I'm concerned for everybody's safety, because someone is carrying around an assault rifle."

Some praised authorities for their handling of the situation. Nancy Cummings, whose son is in first grade, said in a phone interview that she was put at ease by communication from police and the school district.

"I don't assume the man means harm," said Cummings, 41. "It's just unnerving."

Police said they tried to suggest other ways the man could make an impact, such as wearing a shirt or a hat promoting gun rights or petitioning legislators.

"Reasonable people can get together and disagree," Molloy said. "But when we start causing unnecessary alarm to the public, and putting people in the position where emotions are high and the possibility of violence exists, we're not doing anybody any good by doing that."