I was living in pittsburgh at the time:
http://en.wikipedia.org/wiki/Nick_PerryPennsylvania Lottery fix of 1980
In 1977, Perry became the host of the live nightly broadcast of the Pennsylvania Lottery, which was then held in the studios of WTAE in Pittsburgh. On the night of April 24, 1980, more than six million viewers watched as 666 was pulled as the winning number. (Contrary to popular belief, Perry was only an announcer and never drew the winning numbers. This was always done by a senior citizen volunteer, as the lottery benefits senior citizens in Pennsylvania.) Lottery authorities and local bookmakers became suspicious when they noticed a large number of tickets were purchased for certain numbers, and a handful of players came forward to claim approximately $1.8 million of the then record $3.5 million payout. However, they had no actual evidence that the drawing was fixed.
The scheme was masterminded by Perry, who first discussed the idea with two of his business partners, brothers Peter Maragos and Jack Maragos, whom he worked with in the vending business. Once committed to the plan, Perry approached local Pittsburgh lettering expert and WTAE art director Joseph Bock about creating weighted ping-ping balls that were replicas of the official balls used in the lottery machines. Bock agreed to help, and experimented with powder and other substances until he settled on white latex paint. Bock performed careful experiments to determine just the right amount of paint to use so that the weighted balls could fly up off the bottom of the machine, but not high enough to reach the vacuum tube so the ball would be drawn out of the machine. The men thought it would be too risky to weight nine of the ten balls for each machine, so they decided to leave both the 4 and 6 balls unchanged. Those would be the only balls light enough to actually be drawn. This would reduce the number of possible combinations that could come up to eight: 444, 446, 464, 466, 644, 646, 664, or 666. Bock then applied labels on the balls (obtained from an art supply store) that matched those of the originals.
However, Perry needed more help to pull the scheme off. Perry got access to the machines and ping pong balls through the involvement of Pennsylvania Lottery official Edward Plevel. Plevel left the machines and balls unguarded for several minutes on a few occasions. Perry also got WTAE stagehand Fred Luman to actually switch the original balls with the weighted ones before and after the drawing. Bock then took the balls back to his studio and burned them in a paint can half an hour after the on-air drawing was done.
The Maragos brothers, on the date of the drawing, travelled around Pennsylvania buying large quantities of tickets containing the eight possible numbers. The investigation was broken open with an anonymous tip led to a bar near Philadelphia where the Maragos brothers bought a large number of lottery tickets. An employee remembers the Maragos brothers coming into the bar with a platinum blonde woman and laying down a large amount of cash to buy lottery tickets, all on eight specific numbers. While the employee worked the lottery machine to print the tickets, he remembered that one of the Maragos brothers used the pay phone to make a call, spoke in a foreign language, and held up the phone so the listener could hear the lottery machine printing the tickets. Investigators pulled the phone records and traced the call to the WTAE announcer's booth in the studio where the drawing was done. They had successfully implicated Perry, but also knew he could not have acted alone. Further investigation and questioning of the Maragos brothers eventually implicated the rest of the men.