A "mystery gunman" has lately been terrorizing the residents of an Upper East Side apartment building, firing lone bullets into (ostensibly) random living rooms. The NY Post reports that police "think it's some a-hole standing on a balcony shooting across the river" from Roosevelt Island. Tenants have been on edge since Thursday night, when the first bullet shattered a 14th-floor window.

"I'm petrified for my life," Ilene Epstein, a 55-year-old resident of One East River Place, told the Post. "I moved into this apartment because of the river. I have beautiful views. [But] I'll move out of my building before I walk around with a bulletproof vest."

One East River Place stands 50 stories tall, looming over the expanse between 72nd and 73rd Streets and—as the name suggests—looking out over the East River towards Roosevelt Island. According to the NYPD, the sound of breaking glass awoke the first tenant, a 68-year-old woman, around 11:30 p.m. on Thursday night. She awoke the next morning to find a bullet fragment on her floor—blanketed with broken glass from her shattered window—and called the police. According to the Post, authorities believe the ammo came from a .38-caliber Smith & Wesson handgun.

Then, around 1 a.m. on Saturday morning, a 61-year-old resident of the 32nd floor awoke with a bang after a bullet whizzed through her living room window. According to authorities, the bullet left a puncture hole in the bottom of the window, spider-webbing the rest of the glass. No further gunfire has been reported since.

Police matched the timing to two 911 calls from the Manhattan Park apartments on Roosevelt Island, directly across the river from this UES luxury tower, regarding gunshots. Investigating those reports, authorities found no ballistic evidence and identified no victims—quite possibly because those bullets had lodged in apartments across the water.

No one has reported injuries, but the atmosphere in One East River Place remains understandably tense.

"My wife is in Long Island with our baby. Maybe I should call her and tell her to stay there for a few days," Arik Cohen, a 37-year-old computer programmer, told the Post. "I'm already planning on leaving New York. This is just one more reason."

"I'm paying close to $10,000 per month in rent so I can use the fitness center and be shot in the head in my apartment," another tenant added.