NEW YORK (CBSNewYork) -- A man seeking medical treatment on Tuesday afternoon was shot inside of Jacobi Medical Center.
The NYPD is still searching for the gunman, CBS2's Aundrea Cline-Thomas reported.
Police believe it was a targeted attack, adding the victim underwent surgery and is expected to recover.
"I'm visiting my mother, saying goodbyes, and I hear 'active shooter,'" hospital visitor David Rivera said.
"I didn't see anything. I just heard and ran, heard and ran, heard and ran," patient Christopher Betances added.
What Betances heard were gunshots in the waiting area of Jacobi Medical Center's emergency room around 12:30 p.m.
"I heard the first one and I ran into the room," Betances said.
He barricaded himself inside of a patient room with others as police responded, blocking the entrances to the hospital.
"I was scared for my life," Betances said.
"You don't expect it to happen in the hospital, so, a little shooken up," another person said.
However, the gunman was already gone.
In surveillance video, everything seems calm until the gunman brings out his gun and runs through innocent bystanders in the emergency room waiting area, heading toward the 35-year-old victim a few steps away.
Police say the victim was waiting to see a doctor when the suspect came to visit a patient. Investigators believe the two previously knew each other and recognized one another inside.
According to police, there were at least looks exchanged, but maybe not even words before the suspect fired four shots, striking the victim once in the left forearm.
"We heard the commotion and everybody started running and we didn't know what was going on. We heard someone had gotten shot and we couldn't believe it because we are in a hospital," visitor Nancy Rivera said.
Police said the gunman was wearing all black. The handful of staff, patients and visitors who witnessed the whole ordeal were unharmed.
"Just because you have a gun doesn't mean that you have a right to terrorize our communities. I'm telling you to stop it. This is a hospital. This is someone getting care in emergency. How dare you," City Councilwoman Marjorie Velazquez said.
"The mayor needs to step up because this is getting ridiculous," patient Rosie Martinez told CBS2's Ali Bauman. "People can't even come to the emergency room now?"
"We need to work together to get these guns off our streets," Velazquez said.
Before Mayor Eric Adams came to the hospital to visit the victim, he spent the day defending his new plans to combat the city's gun violence, which includes bringing back a new version of the NYPD's anti-gun unit.
READ MORE: Mayor Eric Adams Insists Reimagined Anti-Crime Unit, Other Measures Will Be Effective, Not Abusive
NYC Health + Hospitals released a statement, which said, in part, "This was a cowardly act in a space where New Yorkers come for healing and care. Our health care heroes swiftly took care of the shooting victim and took actions to protect the other patients in the waiting room. Our immediate focus is on caring for the patient and ensuring the safety of our staff. We are working closely with the NYPD as they conduct their investigation."
Jacobi joined a growing list of crime scenes in the city, as detectives are left to piece together what happened.
Police are reviewing all of all of the video in the hospital to see where the suspect fled. They are also canvassing the neighborhood.
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