An off-duty FBI agent whose firearm discharged while he was dancing at a Denver nightclub, striking another patron in the leg, was formally charged with second-degree assault Tuesday.

Prosecutors said that 29-year-old Chase Bishop could face additional charges depending on the results of a blood alcohol analysis.

"We are filing this charge now rather than waiting until the BAC report is received, which we understand could take another week, because sufficient evidence has been presented to file it," Denver District Attorney Beth McCann said in a statement obtained by KDVR. "If an additional charge needs to be filed after further evidence is received, we can file those charges then."

Police have said Bishop was dancing at the downtown Mile High Spirits Distillery and Tasting Bar on June 2 when the gun fell out of his waistband holster onto the floor. The firearm went off when the agent picked it up, striking patron Tom Reddington in the leg.

"We sat down at one of those picnic tables -- I heard a loud bang and I thought some idiot set off a firecracker," Reddington told ABC News' "Good Morning America" last week.

"Then I looked down at my leg and see some brown residue ... I'm still thinking it's a firework ... all of a sudden from the knee down my leg became completely red. And that's when it clicked in my head, 'Oh, I've been shot.'"

The owners of the distillery released a statement on Facebook saying that the agent had violated the facility's rules by carrying a loaded firearm into the tasting room.

"We are deeply saddened by the events that occurred and look forward to speaking with representatives of the FBI, so we can come to understand his presence and his need to be armed in our establishment," it said.

The distillery also offered Reddington "complimentary drinks forever."

The Associated Press contributed to this report.

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