My dad was there..
 

Roosevelt Raceway- Riot at the racetrack - 1963 - YouTube

Nov. 8, 1963: A half-hour after Speedy Scot's triumphant victory in the Dexter Cup Trot, the worst riots in the history of horse racing in New York State ensued at Roosevelt Raceway. There was an accident which disabled six horses near the three-quarter mark in the sixth race, and only two horses finished the race. Knight Deposit and Delaway, were declared the official one-two finishers by the judges. Hundreds of angry bettors went on a rampage, smashing the tote board, setting fires and shattering glass doors. Things became so intense that Roosevelt's security chief, Conrad H. Rothengast, collapsed and died of a heart attack. One hundred and fifty Nassau County police officers arrived in sixty-five patrol cars, and attempted to bring the mob under control. Patrolman Frank O'Neill, one of the first of 150 officers frantically summoned to help track police, was beaten to the ground by a group of 20. "They were like animals", said Jack E. Lee of the Long Island Press, who watched the riot from the press box high above the stands.

Numerous fans jumped over the rail and smashed all the lights on the Tote board. The judge's booths were attacked, and John DeMatteo, one of the judges, was injured. Program booths were destroyed and cars were damaged. A sulky was set on fire in the middle of the track. The fire department had to use hoses to keep fans from interfering with firemen who were attempting to put fires out around the track. Fifteen people were transported to the hospital. One policeman was badly beaten.

The accident occurred when the second horse, Lynch Hanover, driven by Joe MacDonald, attempted to pass the leader, Waygone, driven by Robert Frame. Lynch Hanover stepped into a wheel on Waygone's sulky, and down they went. The judges posted prices of $35 and $14.50 for Knight Deposit and $6.10 and $7.30 for Delaway. Two drivers, Joseph McAlduff and Hugh Bell, were transported to the hospital.

At one point, you can see the flash from an officers gun, as he fired a round into the trac

Thanks...only thought that sort of thing had happened at Yonkers.

Same thing happened in the 80's at Los Alamitos (Yes they used to have harness racing for a brief time). My leading horse, Wintario was about to
get swallowed up at the 1/8 pole but the two horses passing him tangled
and created a pile up. I think I got $9.00 win mutuel on a horse that should have finished 4th or 5th. There was no rioting though, especially from me as I had $450 and should have had zero as I bet my last $100.
Over the course of time I know I have benefited from accidents more often than not.

"the worst riots in the history of horse racing in New York"

You mean there have been others?? New Yorkers.....gotta love 'em.

My father-in-law was young Nassau County police officer who, like every other available patrolman, was summoned ASAP to Roosevelt that night to quell the riot. He still talks about the crazy scene he witnessed. I'll show him the you tube clip, he'll get a kick out of it. Gonna watch it closely tonight with my wife on off chance that we might spot him amongst the men in blue. Thanks for posting.