A pickup truck driver is suspected of being distracted by his cell phone when he failed to obey a stop sign and caused a collision in southern Minnesota that killed the other motorist, according to a criminal complaint.

Hunter Joseph Conrad, 19, of Morristown, Minn., was charged in Steele County District Court last week with criminal vehicular homicide in connection with the crash on May 28 that killed Jacquelyn Olson Ostlund, 79, of Medford, Minn., at NW. 50th Street and N. Cedar Avenue in Owatonna.

"Based on phone data and other known factors," the complaint read, the State Patrol "concluded Conrad was actively using his phone in the minutes leading up to the crash, if not at the time of the crash. Additionally, Conrad did not attempt to slow or stop at the stop sign before striking [Ostlund's] Volvo."

Conrad was charged by summons and is due in court on Sept. 16. Court records do not list an attorney for him, and messages for Conrad have yet to be returned.

According to the complaint:

Ostlund was taken to a hospital by air ambulance before she died.

Conrad told a deputy at the scene that he was driving up the hill while pulling a flatbed trailer and insisted he was not holding or looking at his cellphone at the time of the crash.

He said he slowed down, but did not stop at the stop sign, when he entered the intersection and collided with Ostlund's car.

Analysis of Conrad's cellphone by the state Bureau of Criminal Apprehension revealed that it was open to Instagram and a message was sent from that app in the moments before the crash. His pickup's "black box" showed he was driving at 55 to 60 miles per hour and not braking when he hit the car.