Image copyright Reuters Image caption Jason Dalton faces life in prison if convicted in the shooting deaths

An Uber driver who is accused of killing six people in the US state of Michigan has told police that the Uber app took over his "mind and body", setting off his shooting spree.

Police said Jason Dalton, 45, carried out the shootings on 20 February while working for the ride-sharing company.

"When I logged onto [the Uber app], it started making me feel like a puppet," Mr Dalton told investigators.

He claims that the smartphone program told him to kill his victims.

Although none of the victims were Uber customers, police said Mr Dalton continued to pick up passengers during the shooting spree in Kalamazoo, a small city about 150 miles (241km) west of Detroit.

Uber has said Mr Dalton underwent background checks, but passed because he had no criminal record.

Investigators made Mr Dalton's comments public in response to a local television station's Freedom of Information Act request.

According to documents released on Monday, Mr Dalton said the horned cow head of a devil would appear on his phone screen and give him an assignment.

One of the investigators wrote in the report: "I asked Dalton what made him get his gun tonight, and he said the Uber app made him."

Image copyright AP Image caption Six people were killed during the shooting spree

Mr Dalton is charged with shooting eight people, killing six of them during a five-hour period.

Police have said Mr Dalton did not know any of the victims and they appeared to be selected at random.

He will undergo a court-ordered mental competency exam, but the results will not affect his criminal responsibility for the shootings.

If convicted, Mr Dalton could be sentenced to life in prison. Michigan does not have the death penalty.