According to authorities, Dalton, a married father of two, shot eight people in three locations across the county of 321,000 people Saturday evening in what Prosecuting Attorney Jeffrey Getting said Monday were "very deliberate killings."
In between shootings, the Uber driver picked up fares, according to a source close to the investigation.
"This wasn't hurried in any way, shape or form," Getting said of the shootings, two of which were captured on video. "They were intentional, deliberate and, I don't want to say casually done. Coldly done is what I want to say."
Police: Dalton said he 'took people's lives'
Dalton was charged Monday with six counts of murder, two counts of assault with intent to commit murder and eight firearms charges.
At a probable cause hearing just before an arraignment, detectives testified that Dalton told them he "took people's lives," after he was read his rights that included the right to remain silent.
Dalton appeared in court via video, wearing black glasses and an orange jumpsuit. He showed no emotion as the charges against him were read. A judge denied bail.
The only thing apparently connecting the victims? According to police, just Dalton and his semi-automatic pistol -- which is consistent with the shell casings found at each scene, authorities said.
"He chose people and he shot them simply because he could," Getting told CNN's "Erin Burnett OutFront."
The Dalton family released a statement expressing their condolences to the families of the victims.
"This type of violence has no place in our society, and we express our love and support for everyone involved. We intend to cooperate in every way that we can to help determine why and how this occurred," it read.
While Kalamazoo County Sheriff Richard Fuller said Dalton is cooperating with investigators, there are no clear answers as to what touched off the shooting spree.
"My best sense is that it was somebody who was having an issue at the time and for whatever reason they decided to do what they did," he told CNN's "New Day" on Monday.
Timeline of the shootings
At 3 p.m. Saturday, less than three hours before the shootings began, Dalton walked into Southwick's, a gun shop in Plainwell where he was a regular customer, according to owner Jonathan Southwick. While in the store, Dalton smiled, laughed and hugged an employee, Southwick said, before purchasing a "heavy duty" jacket that could conceal a small pistol.
In less than 10 minutes at the store, Southwick said, Dalton never gave him any reason to be alarmed.
The first shooting occurred around 5:42 p.m. Saturday.
According to police, investigators believe Dalton first shot a woman identified as Tiana Carruthers in front of her children in an apartment complex parking lot. She was struck multiple times but is expected to survive.
Four hours later, the gunman killed Richard Smith, 53, and his son Tyler, 17, at a car dealership, police said.
Tyler's 17-year-old girlfriend witnessed the shootings from the back seat of their car.
"The suspect got out of his car. Walked up to them shot them and then left," Public Safety Director Jeff Hadley said. "Cold blooded."
Then he drove to a Cracker Barrel restaurant and opened fire in the parking lot, killing four women and grievously wounding a 14-year-old girl, police said.
Police identified the dead in those shootings as Dorothy Brown, 74; Barbara Hawthorne, 68; Mary Lou Nye, 62; and Mary Jo Nye, 60.
The 14-year-old girl was in the passenger seat of one of the vehicles and is in critical condition. Hadley said Monday the girl is "still holding on" and responding to verbal commands. Her family identified her as Abigail Kopf.
Two hours after the final shooting, police arrested Dalton without incident in downtown Kalamazoo, police said. Eleven rifles were found at his home, a law enforcement official told CNN.
'He was your average Joe'
Matt Mellen told CNN he rode in Dalton's car just before the shootings started.
"We got about a mile from my house, and he received a telephone call," Mellen told CNN's "AC360." Dalton told the caller he had a passenger in the car and would call the person back, according to Mellen.
"Once he hung up with that phone call is when he started driving erratically," Mellen said, recounting side-swiping a car, running a stop sign and red lights.
"I was pleading with him to stop the vehicle so he could let me out. He was surprisingly calm the whole time."
Mellen said he was able to jump out of the car and call 911.
reported that another man told the station he sought an Uber ride as a safer alternative to walking with a killer on the loose, only to end up, apparently, in Dalton's car.
"I kind of jokingly said to the driver, 'You're not the shooter, are you?' He gave me some sort of a 'no' response ... shook his head," the station quoted the man, whom it identified only as Derek, as saying.
"I said, 'Are you sure?' And he said, 'No, I'm not, I'm just tired.' And we proceeded to have a pretty normal conversation after that."
Uber's chief security officer told CNN that Dalton passed a background check. Police also said Dalton did not have a criminal record.
"For all intents and purposes, he was your average Joe," said Hadley, the public safety chief. "This was random."