He was shot and killed by police.
The evidence includes footage from body police cameras and security cameras from around Fountain Square and Fifth Third Center.
There is no word about the suspect's identity or a motive at this time.
Leonard Cain, one onlooker, told the Cincinnati Enquirer that he was about to enter the bank when someone warned him about the shooting. "This is abnormal. No other industrialized country has this level of active multiple shootings on a regular basis", Mayor John Cranley said about the shooting.
Sen. Rob Portman (R-OH) said in a brief statement, "My staff and I are following the situation in Cincinnati".
Perez arrived at the location in his own vehicle and parked his auto on a nearby street, Isaac said.
WVXU spoke to Sam McDonald, who was walking to his job at the Fifth Third building Thursday morning when he heard the news. He praised police and other emergency personnel, saying, "It could have been much, much worse". Sammarco posted Thursday on Facebook, asking how officials will explain to his parents "they will never see their son again because of a senseless shooting in a foreign country".
Afterward, police swarmed the gunman's apartment in North Bend, Ohio, about 15 miles west of Cincinnati.
The area around Fountain Square was closed to foot traffic for the investigation. They have been identified as Pruthvi Raj Kandepi, 25, Richard Newcomer, 64, and Luis Felipe Calderón, 48. Fox19 reported that four people had been taken to a local hospital. She works for Fifth Third Bank. "After that I started running". The first four police officers to arrive at the bank spotted Perez raining gunfire in the lobby - and quickly engaged him, Isaac told reporters.
He was born in Pureto Rico and had been living in the city since at least 2015, Isaac said.
Witness Cheryl Eagleson said she was across the street from the bank when she heard "loud pops" from a gun, prompting people to drop to the ground. "This is an American problem, that we as Americans must solve by putting ideology last and human life first", said Cincinnati Mayor John Cranley.
A police spokesman says two victims were treated at UC Medical Center.
The building is located in Fountain Square, a hub for entertainment and dining in the city.
The newspaper said at least one of the victims was shot at an ice cream shop at the corner of the bank's headquarters.
Michael Richardson was outside on a smoke break when he said he heard gunshots coming from the bank lobby.
"Then we knew what was going on", Hanson said.
The area around the skyscraper was shut down until about 9.15am (9pm Singapore time), and police found victims in and around 511 Walnut St, including one who was severely wounded and ended up at an ice cream shop steps from the building.