Correction: An earlier version of this story indicated that a University of Toledo medical student was killed in a St. Louis shooting in 2012. The student, Halley Briglia, survived the shooting. 

LEXINGTON, Ky. — A former Perrysburg resident whose life was lost to gunfire just east of the University of Kentucky campus early Friday was a 2012 Maumee Valley Country Day School graduate and student on the UK campus with signs of a promising future.

Jonathan W. Krueger, a junior in UK’s college of communication and information and photo editor of the university’s newspaper, had been telling friends and family members he was looking forward to life after recently turning 22 years old. He was inexplicably robbed and slain about 2 a.m. in what is described as one of UK’s safest and more stable neighborhoods near campus.

“Thank you to everyone who wished me a Happy Birthday today, I can’t believe I’m 22 already! Looking ahead there’s so much to be happy about and if this next year is anything like this last year, then it will be another one to remember!” he posted on his Facebook page Sunday.

Family and friends were mourning his death Friday, an incident that Lexington police said was the result of an early morning robbery.

“This is such a tragedy,” Gary Boehm, head of Maumee Valley Country Day School, said of Mr. Krueger, a former member of the private prep school’s varsity basketball team. “Everybody loved Jonathan ... Jonathan was a very friendly, outgoing, happy person. He was a strong student, a terrific athlete, and a very good teammate.”

Mr. Krueger was pronounced dead about 2:35 a.m. Friday at the University of Kentucky Albert B. Chandler Hospital, according to Susan Straub, spokesman with Lexington Mayor Jim Gray’s office. The Fayette County Coroner’s Office said Mr. Krueger died of a gunshot wound to the chest.

Mr. Krueger’s parents are Walter and Mary Krueger.

Later Friday, Lexington police arrested Justin D. Smith, 18, and Efrain Diaz, 20, both of Lexington, and charged them with murder and robbery. Mr. Smith also is charged with tampering with physical evidence and fleeing and evading, Ms. Straub said.

Mr. Smith is not a UK student, nor is he associated with the university in any other way, Kathy Johnson, a UK spokesman, said.

“We’ve updated the family on our investigation and our thoughts and prayers are with them,” Lexington police Chief Mark Barnard, who talked to Mr. Krueger’s father Friday, said in the statement.

Mr. Krueger was walking with another person on East Maxwell Street near Transylvania Park when the incident occurred.

That part of Lexington has a reputation for being safe. Descriptions from people who work there made it sound similar to the Old Orchard neighborhood near the University of Toledo, with an eclectic mix of stately, historic, and well-maintained homes occupied by UK professors and other professionals.

One of them, Judge Kathy Stein, a former Kentucky state senator, lives on Transylvania within walking distance from where Mr. Krueger was shot.

There’s a church, an elementary school, a florist, a day-care center, and other businesses nearby.

Many of the older houses have been converted into student apartments. The neighborhood’s cozy atmosphere is augmented by a large tract of green space. A $22 million Kroger supermarket recently opened. The shooting occurred three blocks from the UK campus police station that has 82 officers.

One person who works in that neighborhood, a manager for Wassmer Properties, declined to give his name but said the news of Mr. Krueger’s slaying was “like being hit by lightning.”

“It’s a great neighborhood,” he said. “Everybody loves this place. It never happens in this neighborhood.”

Diane Johnson, Wee Care Daycare and Preschool director, located near the shooting site, said the neighborhood apartments are occupied by UK students who “are the sweetest things.”

“I’ve been here since 1985. This is the first time we’ve ever, ever had anything like this in this neighborhood,” Ms. Johnson said.

Maumee Valley Country Day School has scheduled a candlelight vigil for 8 p.m. today. The Reynolds Road entrance will be open by 7:30 p.m., according to a statement issued by Mr. Boehm.

The school has received “dozens of emails of condolence throughout the day and several alumni and friends have come on to campus just to be around one another,” Mr. Boehm said.

“This has been a tough day for all of us as we try to come to terms with the awful reality of Jonathan's death,” his statement said.

Eli Capilouto, UK president, said the university extends its deepest sympathies.

“We have reached out to his family to let them know that we are here to assist them in any way we can at this incomprehensible moment,” he said.

Lexington police were notified about 2 a.m. of the shooting. They found Mr. Krueger lying in the street, according to the mayor’s office.

Another man who was with Mr. Krueger told officers a minivan pulled up and confronted them. He said he was able to escape and found two men outside a nearby home who called police.

Mr. Krueger was a diligent photo editor at the University of Kentucky’s school newspaper, the Kentucky Kernel, Morgan Eads, the paper’s editor-in-chief, said. “He was just an extremely hard worker, very good at his job,” she said. “He was a great photographer. [And] he was as if family to everybody at the Kernel.”

Chris Poore, the student newspaper adviser, agreed.

“He was a great guy, a really hardworking photojournalist, a real student leader here at the newspaper,” Mr. Poore said. “He just finished covering an NCAA basketball tournament in Cleveland and Indianapolis and he did a wonderful job. He always did.”

University of Kentucky police Chief Joe Monroe said the department increased patrols on campus because of the fatal shooting of Mr. Krueger and will continue to do so despite the arrest of Mr. Smith by Lexington police.

“It still makes people feel safe,” said Chief Monroe, who joined the department in 1994. “We are increasing our patrols in that general area.”

According to FBI crime statistics going back to 2007, the 30,000-student campus has not had a homicide. However, reported assaults at the college have steadily increased during the past seven years. The number of assaults increased to 72 in 2014, a 22 percent jump from the year before.

Chief Monroe said the college employs 64 officers, making it the 11th largest police department in the state. The department has detectives and narcotics divisions, two canine units, and bicycle patrol, he said.

He said the university was ranked in a story published about six years ago by Reader’s Digest as one of the top 10 safest campuses in the country.

Chief Monroe said Mr. Krueger was attacked about two blocks from his residence on Woodland Avenue, where he was living with his older brother, William Krueger.

The victim’s family declined to comment.

In 2006, a University of Toledo criminal justice student, Andrew M. Brown, killed his girlfriend, Michelle Danielle Mielecki, a UT marketing student, by shooting her seven times in his South Toledo apartment complex before shooting himself in the head. Both were 21 and 2003 graduates of Wapakoneta High.

Staff writers Tom Henry, Mark Reiter, and Mike Sigov contributed to this report, as did the Associated Press.

First Published April 18, 2015, 4:00 a.m.