NEW YORK (CBSNewYork) -- A graduate student was killed and a student from Italy was injured in stabbings just minutes apart near Morningside Park Thursday night.
Just a short time later, officers responded to another call about a 27-year-old man stabbed near West 110th Street and Cathedral Parkway.
As CBS2's Andrea Grymes reports, police tape and flowers mark the spot where investigators found Columbia graduate student Davide Giri, 30, stabbed in the stomach.
Police sources say a known gang member randomly targeted Giri, killing him, and leaving neighbors who didn't even know him heartbroken.
"Comes here to study and live his dreams, goes to the best school in the world, and someone just comes up and stabs him?" one neighbor said. "It's horrible."
The violence didn't stop there. Police sources say the suspect also randomly stabbed and injured another a 27-year-old man from Italy.
The suspect allegedly threatened another man nearby in Central Park when police caught him with the knife.
"It's awful. My husband and I, we just moved here from California about two months ago and, you know, we know, always be careful like walking in the park and everything," said Morningside Heights resident Bri Keating.
The suspect has been identified as Vincent Pinkney, 25, of Washington Heights. Sources say he's a gang member based in Queens who has 16 prior arrests and was out on parole after serving four years behind bars for gang assault.
He's also being considered a suspect in another non-fatal stabbing that happened in Morningside Park on Wednesday morning.
Pinkney's alleged rampage happened near the same park where 18-year-old Barnard College first year student Tessa Majors was killed two years ago. Another gang member, who was 14 at the time, was arrested and sentenced to nine years to life for her murder.
"There's been police presence, but maybe there needs to be more?" said Morningside Heights resident Carlos Perea. "We moved in shortly after what happened with Tessa, which was really unfortunate obviously."
"It's heartbreaking. It's heartbreaking," Keating said.
Friends told CBS2's John Dias that Giri was on his way home from soccer practice when he was killed.
"Oh my God, wow," said Alex Starzyk, as she learned the news of her next door neighbor's death. "It's so tragic for the intellectual community and Columbia community."
The 30-year-old was a Ph.D. candidate in computer science and the prestigious university, a former teaching assistant with an impressive resume of awards and scholarships, and he was part of a football club.
"This news is both unspeakably sad and deeply shocking, as it took place only steps from our campus. The University is working closely with NYPD to learn more details of the attack and, of course, we will keep you updated as we learn more," Columbia University President Lee Bollinger said in a statement. "These are moments when being in a community really matters. I, therefore, encourage you to seek out and be with others, who will need you as much as you need them. Also, please take advantage of the many University resources that can provide comfort and support."
Students Dias spoke with said they are terrified.
"I'm just still trying to sort of wrap my head around it," John Einarsson said.
"Definitely makes me want to be a little more cautious, especially at night," Abby Hodonicky added.
"What's going on with the violence, man. Lot of people getting hurt, lot of innocent people," said Morningside Heights resident Alfredo Verrios.
"I know there have been other cases in the past, so we usually try to avoid it," one person told Dias.
"The park's a real problem, it's been a problem for decades," Morningside Heights resident Brendan Smith said. "They try to police it."
"We're trying to figure out ways of how to protect ourselves. Some students are looking into getting mace. Some students are looking into making sure we're always walking home together," student Lena Arkwai said.
Arkwai told CBS2's Thalia Perez it's all unnerving. She lives steps from the park.
"I think the student body is a little bit terrified. We all are shaken up a little bit because it just hit so close to home. It was only four blocks from school," Arkwai said.
Many students regularly walk through or near the park. The violence there has led some to take the long way around.
"Like I said, it makes me not want to go through the park. Like, I'm going around right now to go to the gym," said Boudreaux.
"I'm like a little bit stressed, but fingers crossed," said Laura Ruiz Vurguera, a tourist from Spain.
Meanwhile, the second victim, a 27-year-old man, is expected to be OK.
Ashley Thomas is the victim's new roommate. She says he moved in on Wednesday and told her he was a student from Italy.
"He seemed fine," she said. "It's unfortunate to anyone, regardless if they just moved or if they've been living here for years. I mean, it just seems like it's not really a safe place to be."
After the two stabbings, Gregory Johnson says Pinkney threatened him with a knife, but fortunately he wasn't hurt and was able to help police nab the suspect.
Pinkney is facing multiple charges, including murder, assault and menacing, among other crimes.
So far, there's no word on a motive.
John Dias and Thalia Perez contributed to this report.
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