RICHMOND, Va. — The prosecutor in the investigation of a possible dog fighting operation at a house owned by Alanta Falcons quarterback Michael Vick is confident charges will be brought. He can’t yet say who will be charged.

Police raided the home as part of a drug investigation on April 25. They seized 66 dogs, 55 of them pit bulls, and equipment that could be associated with dog fighting.

The investigation is focused on dog fighting because while some equipment seized could be typical of a legitimate breeding operation, which Vick is registered to have, there also was a “pry bar” used to pry apart a dog’s jaws, and bloodstained carpeting.

The bloodied carpet was seized during the raid, and investigators said he saw what appeared to be blood spatters on the floor of a room inside the home above the garage.

“The floor was not drenched in blood, but there were specks that appeared to me to be blood,” he said.

Since the raid, investigators said, erroneous reports have surfaced that the dogs were malnourished and that many had scarring and injuries consistent with dog fighting. The dogs, he said, appeared largely to have been well cared for, and the only one that required immediate veterinary care had a broken leg because of a birth defect.

He said there has been difficulty finding someone who specializes in canine forensics, and an absence of eyewitnesses who can confirm that dog fighting took place on the property.

Vick has contended all along he rarely visited the home, where his cousin, Davon Boddie, lived, and he put the home up for sale shortly after the investigation was started. He agreed to a sale price with a buyer on the first day.

A native of Newport News who starred at Virginia Tech, Vick has blamed family members for taking advantage of his generosity. He said he didn’t know a large kennel on the property could be involved in criminal activity.

Earlier Friday, People for the Ethical Treatment of Animals sent a letter to NFL commissioner Roger Goodell offering to conduct a free humane education course — or “animal sensitivity training” — for NFL players and staff members.

The NFL’s offices were closed Friday for the holiday weekend, but spokesman Greg Aiello said “We are taking this issue very seriously and monitoring the Michael Vick investigation.”