Jason Dalton is accused of going on a killing spree Feb. 20 while working as a driver for the personal taxi service.
He told investigators he was directed where to go and who to kill by symbols on the app, according to documents released Monday.
According to the documents, Dalton believed the app had taken over while he allegedly killed a father and son shopping for a car and a group of four people in a Cracker Barrel restaurant parking lot.
"I asked Dalton why he was carrying his firearm tonight and he said that the Uber App literally took over his body and mind," the documents read. "Dalton explained that when the (Uber) symbol turns to black, it literally has control over you."
Two of his alleged victims survived.
In the interview, police say Dalton told them a "devil figure as a horned cow head or something like that... would give you an assignment and it would literally take over your whole body."
Dalton, 45, also described the mechanism behind the app's control over him as "artificial intelligence," police say.
"Dalton then told us that it feels like it is coming from the phone itself and he didn't know how to describe that... Dalton said that as he was sitting there with us, it was almost like artificial intelligence that can tap into your body," the report says.
Dalton claimed he could not recall the murders because he wasn't in control of his body, but said he was sorry for them, according to the documents.
To the parents of the teen killed with his father, the documents say Dalton said: "I'm sorry."
The victims were all strangers to Dalton, police say. He has not yet entered a plea.
A call made to Dalton's attorney went to voicemail and was not immediately returned Tuesday morning.
The horror began at a Kalamazoo County apartment complex, where police say Dalton shot a woman multiple times as she protected a group of children.
Fifteen miles away, a father and son were shot dead about four hours later as they shopped for a car at a dealership.
Minutes later, a hail of bullets in a nearby Cracker Barrel restaurant parking lot left four dead and a 14-year-old girl injured in two separate cars.
Dalton, a father of two, was arrested after his car was spotted by a deputy.
Dalton has been ordered to undergo a mental competency exam. He stands charged with six counts of murder and with attempted murder.