The family of the suspected gunman, 25-year-old Connor Sturgeon, issued a statement Monday night expressing their sorrow, also saying "there were never any warning signs or indications he was capable of this shocking act."

"No words can express our sorrow, anguish, and horror at the unthinkable harm our son Connor inflicted on innocent people, their families, and the entire Louisville community," the Sturgeon family said. "We mourn their loss and that of our son, Connor. We pray for everyone traumatized by his senseless acts of violence and are deeply grateful for the bravery and heroism of the Louisville Metropolitan Police Department."

"While Connor, like many of his contemporaries, had mental health challenges which we, as a family, were actively addressing, there were never any warning signs or indications he was capable of this shocking act," the family said. "While we have many unanswered questions, we will continue to cooperate fully with law enforcement officials and do all we can to aid everyone in understanding why and how this happened."

-ABC News' Alondra Valle

Louisville Deputy Chief Paul Humphrey provided a timeline of the police response to Monday's shooting while sharing body camera footage from the responding officers:

--8:38 a.m.: Officers dispatched.

--8:41 a.m.: Officers Nickolas Wilt and Cory Galloway pull up to an entrance to the bank. Gunshots are immediately fired in their direction, forcing them to back up the car.

--8:42 a.m.: They exit the vehicle.

--8:44 a.m.: Wilt is struck and officers return fire. When Wilt is struck, Galloway is heard yelling, "He’s down! Get the officer!”

--8:45 a.m.: After a short barrage of gunfire, officers make entry to the bank and confirm the suspect is down.

-ABC News' Will McDuffie

Louisville police have released body camera footage from Monday's mass shooting.

The footage shows the interaction between the shooter and responding officers, including Nickolas Wilt, who was shot and remains in critical condition.

"You will see he never hesitates," Deputy Chief Paul Humphrey said of Wilt during a press briefing on the footage. "This young man went back in to the line of fire."

Humphrey said the suspect "lied in wait" for officers to respond to the bank shooting.

The officers could not see inside the building on their approach, and the footage conveys the "tension" of the scene, Humphrey said.

Officers and EMS treated victims at the scene of the shooting. The actions of first responders "absolutely saved lives," Humphrey said.

Louisville Mayor Craig Greenberg said authorities plan to release 911 audio of the incident within the next 24 hours.

"We know there are still a lot of unanswered questions," Greenberg said at the briefing. "We will continue to provide information as soon as it is available."

Of the eight people injured in Monday's mass shooting, three remain at the University of Louisville Hospital.

One of those patients, 26-year-old police officer Nickolas Wilt, is still in critical condition, hospital officials said, and the other two patients are stable and in fair condition.

Wilt was shot in the head while running toward the gunfire, according to police. Wilt just graduated from the police academy on March 31.

Wilt was on his fourth shift ever when he rushed the shooter, with his field training officer beside him, said Jackie Gwinn-Villaorel, Louisville’s interim police chief.

The training officer, Cory Galloway, shot and killed the suspect, authorities said, while being grazed by a bullet.

Nickolas Wilt, the rookie Louisville police officer shot in the head while responding to Monday's shooting at Old National Bank, is "slowly improving," city authorities told ABC News Wednesday morning.

Wilt remains in critical condition, however. He was the only victim still listed in critical condition.

-ABC News' Will McDuffie