"It was a real brief confrontation...money was thrown up in the air, shots were fired, several people were hurt, it was pandemonium," he recalls.
The hearing opened with selection of jury members as Puff Daddy - real name Sean Combs - looked on. The process is expected to take several days.
The charges stem from a shootout at a city nightclub just over a year ago. Prosecutors say the rapper, who was with his girlfriend, the film star and singer Jennifer Lopez, got into an argument, and several shots were fired.
Puff Daddy was arrested after being driven away at high speed, allegedly with a gun in his car. If convicted, he could face up to 15 years in prison.
Eric Funk, the manager of Club New York, vividly remembers the night when it all happened.
Shots fired
He says Puff Daddy and Ms Lopez had spent their time sitting together in the club's VIP area, but as they were leaving, a row broke out with another patron.
"It was a real brief confrontation...money was thrown up in the air, shots were fired, several people were hurt, it was pandemonium," he recalls.
Sean Combs was arrested shortly after being driven away from the club at high speed. Police say his driver jumped several red lights, there was a gun in his car, and that another weapon had been thrown out of the window.
Both Mr Combs and a tearful Jennifer Lopez spent a night behind bars before he was charged with weapons possession and released on bail.
'I do not own a gun'
Pushing his way through reporters after a recent pre-trial hearing, Mr Combs repeated a denial he has made again and again since the December shootout.
"I do not own a gun, I do not carry a gun," he asserted.
"The charges and allegations against me are 100% false, and I feel confident that I will be vindicated and everything will be all right."
Puff Daddy is relying on some of the best lawyers money can buy to clear his name: Johnnie Cochran, of OJ Simpson fame, and Ben Brafman, best known for defending leading mafia figures.