Cote, a harness driver before becoming a trooper in 1992, already had noticed other horses making miraculous improvements after joining Team Ledford, he said.
On Friday night, Cote's unit arrested four members of the team, closing an 18-month drug investigation called Operation Horsepower, he said.
The arrests stunned the harness-racing world, largely centered at the Meadowlands.
"Someone who takes illegal means to improve their horses is seen as a cheater," said Ellen Harvey, executive director of Harness Racing Communications, a division of the United States Trotting Association.
"If you're an Indy car driver and somebody cuts through the center field, that would outrage you and all the people who are going all the way around," Harvey said. "This is akin to that."
Ledford has not been charged. His son, harness driver Eric S. Ledford, 35, of Middlesex County, was arrested in the drivers' locker room at the Meadowlands and charged with fixing races by doping horses, police said.
Two Ledford employees - Ryan Dailey, 31, an assistant trainer, and his wife, Ardena J. Dailey, 31, a stable hand - were arrested at their home in East Windsor, N.J., and charged with race rigging and drug possession. The team's veterinarian, John R. Witmer, 68, of Freehold, N.J., was charged with conspiracy to rig a contest and supplying drugs to the operation, police said.
A dead horse, Malamar Man, was found during the raid at the Ledford Stable in Englishtown, N.J., and taken to the University of Pennsylvania's New Bolton Center in Chester County to be examined, Cote said.
"He had only been in the barn for a week and had probably died that night or morning," Cote said, adding that the horse showed signs of a substance that would cause its blood to clot.
Troopers sifted yesterday through evidence seized at Ledford Stables and the employees' homes. Cote said searchers at the Daileys' home had found "a substantial amount" of the blood-doping drug Aranesp, which stimulates production of oxygen-transporting red blood cells.
Seldon Ledford trains about 50 horses. All have been forbidden to race until the state Racing Commission decides whether to require blood tests, Cote said.
Eric Ledford is the third-ranked driver at the Meadowlands, the country's most popular venue for harness racing.
Seldon Ledford is the 12th-ranked trainer of harness racers in the nation and won more than $3 million in the 2005 season.
His rise has been stellar, Cote said. Between 1991 and 2003 he averaged about $186,000 in winnings a year. In the first two months of 2006, Ledford's stable won more than $500,000.
Contact staff writer Sam Wood at 856-779-3838 or firstname.lastname@example.org.