NEW YORK (CBSNewYork) — New Yorkers were on edge Monday after a string of random crimes throughout the city.

One of the most violent was an attack on the subway in Lower Manhattan, where a man was caught on camera viciously beating another passenger with a metal object.

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The 59-year-old victim’s skull was fractured and the suspect has since been arrested, but the NYPD maintains there’s no crime wave.

In fact, the department insists crime is actually down.

“These are a couple of individual acts of violence that happened,” NYPD Chief of Department Terrence Monahan said in an exclusive interview with CBS2 political reporter Marcia Kramer. “If you look at each of the three instances we were able to respond quickly and make arrests.”

NYU junior Cat Heinen says being violently ambushed and beaten by a homeless man in the East Village late Saturday has left her scared and shaken.

“I don’t think I can walk alone for a long time,” she told CBS2. “I’ve been walking with my keys in hand.”

Heinen also says she’s bought pepper spray after the terrifying ordeal. While the NYPD was quick to catch the man who attacked Cat and two other women, she says the experience has changed her life.

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“This has been really traumatic and awful,” she said. “He got me right to the ground and kept punching, I’m pretty sure he was going to rape me.”

She’s just the latest victim in a recent string of random crimes. In addition to the East Village assault and Lower Manhattan subway attack, police say a man tried to rape a woman getting out of an Uber on the Upper West Side last week.

The NYPD insists that there’s no crime wave. Statistics for the first six months of the year show overall crime is down another 1.8 percent, from 46,190 to 45,337. While overall stats continue to be low, one problem area is rapes. Statistics show rapes are up 34 percent; 912 from the first six months of 2018 compared to 680 in 2017.

In terms of the random crimes seen recently, what is the city doing to assure people they’re safe?

“Listen, this is a city of 8.6 million people, there are going to be incidents that happen,” Monahan said. “The NYPD is the best at keeping people safe and we’re out there. If there are some individualized acts of violent crime that take place, rest assured we’re going to go after the small amount of individuals that perpetuate them.”

In this era of social media, Monahan urges New Yorkers who see crimes to take pictures and share them with cops to help solve crimes like the subway attack quicker.

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The NYPD will have extra officers on the streets this summer. 300 will be part of “Operation All Out,” and 750 just graduated from the police academy.