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Authorities nationwide are probing whether a recent string of random attacks on pedestrians are part of a violent game called "knockout," where unsuspecting passersby are targeted with the intention of knocking them out cold with a single punch.

At least two deaths have been linked to the game this year and police have seen a recent spike in similar attacks. Authorities and psychologists say the concept has been around for decades — or longer — and it's played mostly by impulsive teenage boys looking to impress their friends.

New York City police have deployed additional officers to city neighborhoods where at least seven attacks occurred in the past few weeks, including the assault on the 78-year-old woman. Police Commissioner Raymond Kelly said some are smacked, some are more seriously assaulted, and some harassed. The department's hate crimes task force is investigating, because some attacks have been against Orthodox Jews in Brooklyn.

In Philadelphia, two attacks may be related to the game.

MyFoxPhilly.com reported that two bus passengers were assaulted in separate incidents in which the suspects ran off after punching the unsuspecting victims. No arrests have been made.

"It's just knuckle headedness. It's just bizarre behavior on the part of somebody to intentionally hurt someone? It's unexplainable," Southeastern Pennsylvania Transportation Authority Police Chief Thomas Nestel told the station.

In Lower Merion, a suburb near Philadelphia, two 19-year-olds were charged with knocking down a 63-year-old man out walking his dog the evening of Oct. 29. They were arrested nearby a short time later, and have been charged with assault, police Lt. Frank Higgins said.

"We do worry that it's something like that ... because we've had two similar assaults, neither one of which resulted in a robbery," Higgins told The Associated Press.

In September in Jersey City, N.J., two 13-year-olds and a 14-year-old were charged as juveniles in the murder of 46-year-old Ralph Eric Santiago. He was found Sept. 10 with his neck broken and his head wedged between iron fence posts. Hudson County Prosecutor's Office spokesman Gene Rubino has said prosecutors believe the teens were playing the game.

In Washington, D.C., police were investigating two assaults in the past week, both of which resulted in minor injuries but not unconsciousness.

Phoebe Connolly, of Brattleboro, Vt., told Fox News' Greta Van Susteren she was punched in the face by a teenage while she was riding her bike in the Columbia Heights neighborhood of Washington. The suspect, who was also on a bike, was traveling in a group with other teens.

"I said. 'Excuse me,' as I biked through the group, and when we passed each other, he reached out with his left hand and punched me in the face," Connolly said on "On the Record."

Connolly, 32, said she was told to research "knockout" on the Internet and came across a news article about a woman who was punched in the back of the head while walking at night in the same area. The suspects were also on bikes and laughed while punching the victim.

"Ultimately, I have moved past it and I really have no hard feelings about what has happened. I see it as another reason to support our youth with activities and youth programs," she said.

A New York state legislator has introduced a bill would make the violent game a gang assault with a sentence of up to 25 years. Youths would be charged as adults. The bill may be the first of its kind in the nation, according to the national conference of State legislatures.

Republican Assemblyman Jim Tedisco of Schenectady told The Associated Press on Thursday that his measure is intended to stop the game and avoid more serious injuries. The bill will also include prison time for those who record or watch the assaults.

"It's hard to excuse this behavior, there's no purpose to this," said Jeffrey Butts, a psychologist specializing in juvenile delinquency at the John Jay College of Criminal Justice. "When someone runs into a store and demands money, you can sort of understand why they're doing it, desperation, whatever. But just hitting someone for the sheer thrill of seeing if you can knock someone out is just childish."

In late May in Syracuse, a group of teenagers attempting to knock Michael Daniels out with a single punch wound up beating and stomping him to death, according to police. A 16-year-old was found guilty of manslaughter, and his 13-year-old co-defendant pleaded guilty to assault, admitting he started the fatal beating by trying to knock out Daniels with a single punch. Both were sentenced to 18 months behind bars.

And earlier in May, Elex Murphy, now 20, was sentenced to life in prison plus 25 years in St. Louis for killing a Vietnamese immigrant as part the game in 2011.

The Associated Press contributed to this report.

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