LOUISVILLE, Ky. (AP) — A 23-year-old used a rifle to kill four people — including a close friend of the governor — Monday at the Louisville bank where he was an employee, authorities said.

The shooting, the 15th mass killing in the country this year, comes just two weeks after a former student killed three children and three adults at a Christian elementary school in Nashville, Tennessee, about 160 miles (260 kilometers) to the south. That state’s governor and his wife also had friends killed in that shooting.

Police in Louisville arrived as gunshots were still being fired inside Old National Bank and exchanged fire with the shooter, who died, Louisville Metro Police Department Deputy Chief Paul Humphrey said at a news conference. He said it wasn’t clear whether the shooter killed himself or was shot by officers.

Police Chief Jacquelyn Gwinn-Villaroel identified the shooter as Connor Sturgeon.

Nine people, including two police officers, were treated for injuries from the shooting, University of Louisville Hospital spokeswoman Heather Fountaine said in an email. One of the officers was in critical condition, she said. At least three patients had been discharged.

An emotional Kentucky Gov. Andy Beshear said he lost a friend in the shooting in the building on East Main Street not far from the minor league ballpark Louisville Slugger Field and Waterfront Park.

“This is awful,” he said. “I have a very close friend who didn’t make it today. … And one who’s at the hospital that I hope is going to make it through.”

It was the second time that Beshear was personally touched by a mass tragedy since becoming governor.

In late 2021, one of the towns devastated by tornadoes that tore through Kentucky was Dawson Springs, the hometown of Beshear’s father, former two-term Kentucky Gov. Steve Beshear. Andy Beshear frequently visited Dawson Springs as a boy and has talked emotionally about his father’s hometown.

Beshear spoke as the investigation in Louisville continued and police searched for a motive. Crime scene investigators could be seen marking and photographing numerous bullet holes in the windows near the bank’s front door.

As part of the investigation, police descended on a neighborhood about 5 miles (8 kilometers) south of the downtown shooting. The street was blocked as federal and local officers talked to residents. One home was cordoned off with caution tape.

“I’m almost speechless. You see it on the news but not at home,” said Kami Cooper, 38, who lives in the neighborhood.

A man who fled the building during the shooting told WHAS-TV that the shooter opened fire with a long rifle in a conference room in the back of the building’s first floor.

“Whoever was next to me got shot — blood is on me from it,” he told the news station, pointing to his shirt. He said he fled to a break room and shut the door.

Humphrey, the deputy chief, said the actions of responding police officers undoubtedly saved lives.

“This is a tragic event,” he said. “But it was it was the heroic response of officers that made sure that no more people were more seriously injured than what happened.”

The 15 mass shootings this year are the most during the first 100 days of a calendar year since 2009, when 16 had occurred by April 10, according to a mass killings database maintained by The Associated Press and USA Today in partnership with Northeastern University.

Going back to 2006, the first year for which data has been compiled, the years with the most mass killings were 2019 and 2022, with 45 and 42 mass killings recorded during the entire calendar year. The pace in 2009 slowed later in the year, with 32 mass killings recorded that year.