Here's what we know ... cops were called to a Hooters restaurant in Queens, NY in the early hours of July 20 after gunshots were fired.

We've learned ... witnesses told police Lamar and his group of friends were leaving the restaurant when they got into a verbal altercation with another group. Part of the argument was captured on surveillance.

One witness told cops a man from the other group pulled out a gun and fired multiple shots into the air -- nobody was hit. That group fled the scene, according to the witness.

Law enforcement sources tell us the NYPD is actively searching for the shooter. So far, no arrests have been made.

Odom is not accused of any wrongdoing -- and we're told he's been cooperating with police.

Lamar's attorney Saam Zangeneh tells us "Lamar did nothing wrong and was not arrested."