A retired city worker is facing multiple murder charges after a shooting spree left four people dead in the city of Penticton, B.C., on Monday.

John Brittain, 68, was charged with three counts of first-degree murder and one count of second-degree murder on Tuesday.

Handcuffed, he was led through the back door of the provincial courthouse for a brief, first court appearance at 10:20 a.m. PT and was remanded into custody. He didn't respond to reporters' questions as he was escorted from the courthouse.

Speaking to reporters on Tuesday morning, Penticton Mayor John Vassilaki said Brittain worked for the city's engineering department for several years until his retirement "due to an illness" in 2016.

Brittain's current employer

The president of Ecora Engineering confirmed Brittain is currently employed by the company, and has worked there as a civil engineer since 2017.

"We're shocked and saddened by the incident. Our thoughts and prayers go out to the family and friends of the deceased," said Kelly Sherman, in a statement. "As it's a criminal matter, the RCMP will be investigating, no further comment."

Brittain is led from sheriff's van into the courthouse

John Brittain, 68, is charged with murder after a shooting spree left four people dead on April 15, 2019. 0:30

Brittain's next court appearance has been set for May 8.

Two women and two men were killed in three different locations in the city during an hour-long shooting spree that began around 10:30 a.m. PT Monday, and ended with Brittain turning himself in at the front desk of the local RCMP detachment.

Mounties said the victims, who were in their 60s and 70s, all knew each other and their alleged killer. Investigators believe the shootings were targeted, but a possible motive hasn't been determined.

Mounties said they won't be releasing the names of the victims or details on how they knew the accused, as officers don't believe it will further the investigation, but CBC has learned through friends of Rudi Winter that he is one of the victims. (Rudi Winter/Facebook)

On Tuesday, RCMP Supt. Ted De Jager said Mounties won't be releasing the names of the victims or details on how they knew Brittain, as officers don't believe it will further the investigation.

"I can't speak to the actual relationship and, be mindful, this matter is before the courts," De Jager said during a news conference.

CBC News has learned through friends of Rudi Winter that he is one of the victims.

Police forensic officers investigate after the body of a man who was shot was found outside a home near Lakeview Street and Heales Avenue. (Ben Nelms/CBC)

On Monday, police were first called to the area of Lakeview Street and Heales Avenue, a residential neighbourhood blocks from Okanagan Lake, after receiving reports that a man had been shot at 10:30 a.m. PT.

As officers were en route, police received a second call that another person had been shot further south in the city. The public was asked to avoid the downtown area entirely, or stay indoors if they were already there.

De Jager said a man matching the suspect's description turned himself in, unarmed, at the RCMP detachment on Main Street at 11:27 a.m. PT.

Two victims were found at a home in the 2400 block of Cornwall Drive, near Murray Drive, with a third victim found nearby on Monday. (Ben Nelms/CBC)

Investigators found four bodies in three places. One man was found dead in front of a home on Heales Avenue, while another man and a woman were found dead inside a house in the 2400 block of Cornwall Drive. The second female victim was found nearby.

Mayor Vassilaki said he knew Brittain while they were both working for the city — Vassilaki as a councillor, Brittain in development services with the engineering department.

Police escort John Brittain from the Penticton courthouse after his initial appearance on Tuesday. (Ben Nelms/CBC)

The mayor said he was "saddened" to learn Brittain is now accused of murder.

"He was a gentleman, he did his job well, he was very in favour of what our community was doing, was always involved in community matters — him and his wife," Vassilaki said.

The mayor shook his head when asked if Brittain was known to have a temper.

"Nothing like that at all. Very gentle man."

Mayor talks about Brittain who he knew as a city engineer

Penticton Mayor John Vassilaki shares his impression of murder suspect John Brittain, who worked in the city's engineering department before retiring in 2016. 1:08

Neighbours shaken

Penticton sits between the southern bank of Okanagan Lake and the northern shore of Skaha Lake, with a population of 30,000 that swells with tourists during its hot, dry summers.

Danny Herron, who lives near the Lakeview Street crime scene, said it was frightening to hear shots fired in his neighbourhood.

"It's an eye-opener for everybody," he said Monday. "When it continued on, I thought, 'What's going on here? Is this guy on the loose? Is he shooting randomly?' You just don't know."

Danny Herron and his son, Hayden, live near the Lakeview Street crime scene. Herron said it was frightening to hear shots in his neighbourhood. (Brady Strachan/CBC)

De Jager said RCMP are confident the accused acted alone and that the community isn't in any further danger, but he said the emotional impact will be lasting.

"I recognize these heartbreaking events have a deep impact on the community and will continue to do so for some time," the Mountie said.