The former Bachelor star, who rear-ended Mosher's tractor in his 2008 Chevrolet Silverado truck, called 911 to report the incident, and then allegedly fled the scene. He was later arrested and charged with Leaving the Scene of a Fatality Motor Vehicle Accident (Class D Felony).
According to the criminal complaint obtained by ET, the general probable cause lists "admission/statements, caused property damage, operating motor vehicles, possessed alcoholic beverages/containers, identified by witnesses, near scene of crime and caused personal injury." Soules has not been charged with any alcohol-related offense at this time.
A source close to the Soules family claims he was not drunk at the time of the crash. "The truck Chris was driving was one of the old work trucks they had on the land there," the source tells ET. "Not his everyday truck. He was near his land when the crash happened."
ET can confirm that Soules was driving away from his home when the accident occurred around 8:20 p.m. An additional source claims that the reality star wasn't wearing his seat belt, and he hit the dashboard of his truck. Investigators have not yet been able to interview Soules to confirm whether or not he was in fact wearing his seatbelt. Soules' lawyers are not commenting.
"An onlooker stopped, pulled over and told Chris to call 911. So, he did," the source claims. "Chris climbed out of his passenger side window and called 911."
An Iowa State Patrol official told ET that if you listen to the 911 call, you can hear someone else talking with Soules in the background. According to the United States Census Bureau, the small town has an estimated population of 171 as of 2015.
"In Iowa, when something like this happens, everybody stops," the official noted. "It's a small community, everybody knows everybody. I don't know who was passing by, but somebody stopped and helped with CPR."
As for why Soules may have left the scene of the accident?
The source claims "he was in shock," and also claims that one of his relatives had pulled up to the location.
"[His relative] was nearby on their land and heard the crash," the source alleges. "Then, [Soules and his relative] left at some point."
The Iowa State Patrol official tells ET that the sheriff is looking into who helped Soules allegedly flee the scene, saying, "I was told by a supervisor that they were going to try and find out who was driving that red [Durham] truck."
Authorities would not comment on whether it was a relative who had in fact helped him leave the scene.
Earlier this week, a rep for Soules released a new statement revealing Soules hired three high-powered Des Moines, Iowa, attorneys, who have asked the public "not to prejudge this case based on media coverage." The lawyers also say their client "acted reasonably" in the aftermath of the crash.
Hear the latest on what's next for Soules in the video below.