The Gallatin County Sheriff's department made the announcement in a press statement late Wednesday.
Ben Jacobs, a reporter for The Guardian, called police after he said Gianforte "body-slammed" him for asking a question in the candidate's campaign office. Three Fox News staffers said they witnessed the assault while they were waiting to interview Gianforte.
The maximum penalty if convicted of the assault charge is a $500 fine and 6 months in jail. The Sheriff's department said in its statement that Jacobs' injuries did not meet the legal definition of felony assault.
Guardian reporter Ben Jacobs tweeted after the reported encounter.
Greg Gianforte just body slammed me and broke my glasses— Ben Jacobs (@Bencjacobs) May 24, 2017
A short time later, Jacobs posted audio of the incident.
There was a local TV crew there when Gianforte body slammed me. Audio is posting soon at @GuardianUS— Ben Jacobs (@Bencjacobs) May 24, 2017
In a statement, the Greg Gianforte campaign claims Jacobs "grabbed Greg's wrist and spun away from Greg, pushing them both to the ground.
Late Wednesday night, Fox News producers who were in the room at the time disputed the campaign statement, they say Gianforte grabbed Jacobs by the neck and slammed him to the ground.
They also say at no time did Jacobs show any aggression toward Gianforte.