Police in Missouri say they may have caught the "Indian Creek Killer," a serial murder suspect believed responsible for the deaths of five white middle-aged men in Kansas City over the last year.

Suspect Frederick Demond Scott, 22, allegedly fatally shot the five men between Aug. 19, 2016, and Aug. 13 this year. The first four victims were killed in remote areas, often near hiking spots as they walked dogs or visited parks, authorities said. Three of the men were shot in the back of the head.

Scott was captured following the fifth slaying, when, according to police, he deviated from his pattern of killing in secluded areas and instead attacked a man who had stepped off a bus in broad daylight, the Kansas City Star reported.

The motive for the killings remains unknown, police said, but Scott reportedly said his victims “didn’t see it coming.”

According to court documents from a prior harassment case, Scott threatened in 2014 to shoot up a school “Columbine-style,” a reference to a 1999 mass slaying in Colorado, and wanted to “kill all white people,” the Kansas City Star reported. He was then sentenced to 180 days behind bars, but the sentence was later suspended and Scott was given probation.

The suspect's mother, however, denies her son harbors any race-based hostility.

“As far as I know, Fredrick never had a problem with white people,” she told the Star, adding that, “He would do odd jobs for people and some of those people were white men.”

Scott has so far been charged in two of the murders. All five men were shot with various types of ammunition, but mostly in just one shot, police said.

The most recent victim was 57-year-old Steven Gibbons, who was attacked in broad daylight in Kansas City after stepping off a bus and not noticing that the suspect was following him, police said.

Gibbons was shot in the back of his head while the killer fled the scene on another bus. The injured man survived for a day on life support before succumbing, police said.

Scott was identified through video footage acquired by police. In addition, Scott's DNA was found on a bottle and a cigarette at the scene, police said.

During questioning, Scott admitted his 9mm handgun killed Gibbons, but insisted the weapon fired accidentally, police said.

So far, he has been charged with the murders of Gibbons and John Palmer, 54.

Police said they believe Scott also may have killed David Lenox, 67; Timothy Rice, 57; and Mike Darby, 61.