Washington State authorities say a potential mass shooting was thwarted last Friday night after citizens at a music festival saw a suspicious man and reported him.

Deputies with the Grant County sheriff's office said Saturday they arrested an Ephrata man accused of harboring plans to commit a mass shooting at the Gorge Amphitheater the night before, according to a news release.

Concertgoers and security at the Bass Canyon music festival notified police around 9 p.m. after a suspicious man was seen inhaling an unknown substance or gas from a balloon and then loading two 9mm pistols from the trunk of his car. Witnesses say they saw the man, later identified as 31-year-old Jonathan R. Moody, conceal one of the pistols in the rear of his waistband and another in an outside-the-waistband holster, the Grant County sheriff's office said.

Authorities said the armed suspect approached concertgoers and began asking what time the concert would end and where people would be exiting the venue.

Security at Gorge Amphitheater detained the suspect and disarmed him. After investigating, sheriff's deputies arrested Moody on one count of posession of a dangerous weapon and one count of unlawful carrying or handling of a weapon.

"The Gorge Amphitheater does not allow weapons on site, but Moody’s possession of weapons was not the lone factor for his arrest. Moody’s actions of appearing to inhale an intoxicant, loading weapons in the parking lot, and his questions about where concertgoers would be exiting and at what time, furthered the suspicions of witnesses and deputies. Moody did not make any statements to deputies," authorities said.

Moody was booked in the Grant County Jail.

The Bass Canyon event was a three-day electronic dance music festival hosted at Gorge Amphitheater Aug. 19-21. Friday night's concert was sold out, with more than 25,000 people in attendance, the Grant County sheriff's office said.

Festival organizers issued a statement after the arrest.

"Safety is our top priority. Thank you to the fans who reported him and the venue security and sheriff's department for handling the situation. Always look out for each other, state safe, and remember, if you see something, say something," Bass Canyon said.

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— Bass Canyon (@Bass Canyon) 1661041896

The Grant County sheriff's office also thanked the citizens who reported suspicious activity.

"Remember: if you see something, say something," the sheriff's office said. "Citizens saw something completely out of place for the circumstances and notified security, who in turn notified deputies. That combination of situational awareness along with noticing 'something does not fit' resulted in a possible tragedy being prevented.

"Thank you to the concertgoers who reported this man, and to venue security for keeping the man from getting inside the concert venue."