Scott Brower, chief assistant prosecuting attorney in Kalamazoo County, told NPR that Dalton "acknowledged the facts behind each of the charges", including attempted murder and firearms violations.
Jason Dalton enters the court room before pleading guilty to six counts of murder and several other charges at the Kalamazoo County Courthouse on Monday, Jan. 7, 2019 in Kalamazoo, Michigan.
Tiana Carruthers, who was shot multiple times but survived the attack, told the court that she saw Dalton's face "every time" she goes to sleep, adding: "I hurt every single day".
Four people were killed at a restaurant and two at a vehicle dealership in the shootings in the city of Kalamazoo.
Dalton's motives remain a mystery.
The shootings took place on a Saturday evening at three locations - outside a Cracker Barrel restaurant, a Kia auto dealership and an apartment block.
Police said that following his arrest, Dalton claimed that a "devil figure" on the Uber app was controlling him and driving him to kill on the days he committed the murders. That victim was hospitalized. "All told, six people killed and two were injured".
He later opened fire outside of a local Cracker Barrel, taking the lives of 74-year-old Dorothy Brown, 63-year-old Mary Lou Nye, 60-year-old Mary Jo Nye, and 68-year-old Barbara Hawthorne, authorities said.
Jason Dalton pleaded guilty to killing six people in-between picking up riders for Uber in 2016.
A passenger named Derek, who rode with Dalton between killings on that day, told NPR he got into the Uber ride and "jokingly" asked, "You aren't the shooter, are you?'"
"I've thought about this quite a lot", he said to Lipsey. However, he had been deemed mentally fit to stand trial, and had abandoned a planned defence of insanity last week.
"I don't know whether there will ever be a satisfactory answer as to why he did it ... the "why" question is one that haunts us", Getting said, CNN reported. "Doing this is what's best for the people of this community, it's what's best for our victims".
A sentencing hearing was scheduled for February 5. Victims and victims' families will have a chance to address the court at that time, Getting said.