"In a community like this it's, especially involving the death of a 7-year-old," Ballard said. "I don't think we'll ever be able to wrap our minds around this," Fayette County District Attorney Scott Ballard said.
He said Benoit's 43-year-old wife, Nancy, was killed Friday in an upstairs family room, and her feet and wrists were bound and there was blood under her head, indicating a possible struggle. Daniel, age 7, was probably killed late Saturday or early Sunday, and his body was found in his bed, the district attorney said.
Benoit, 40, apparently hanged himself hours later, Ballard said. His body was found in a downstairs weight room hanging from the pulley of a piece of exercise equipment. Authorities said Benoit placed a Bible next to each of their bodies before killing himself.
World Wrestling Entertainment, based in Stamford, Conn., issued a statement Tuesday saying steroids "were not and could not be related to the cause of death."
"The physical findings announced by authorities indicate deliberation, not rage," the company said, adding that Benoit tested negative April 10, the last time he was tested for drugs.
The WWE instituted a new and supposedly tougher drug policy just last year after the death of another wrestler was linked to steroid use, reported CBS News national correspondent Byron Pitts.
Instead, the WWE said Benoit told co-workers his wife and son had food poisoning and were throwing up.
Authorities offered no motive for the killings, which were spread out over the weekend and discovered Monday. No suicide note was found.
On Saturday, Benoit called a co-worker to say he had missed a flight and would be late for a wrestling event in Texas, WWE said in a timeline posted Tuesday on its Web site. The co-worker said Benoit sounded tired and groggy and said "I love you," which the co-worker found "out of context," WWE said.
When a co-worker who usually travels with Benoit called him later from the Houston airport, Benoit told the co-worker his wife, Nancy, was throwing up blood and that his son, Daniel, also was throwing up. Benoit said he thought it was food poisoning, according to WWE.
After Benoit talked to a WWE Talent Relations representative, the representative suggested Benoit try to make it to a pay-per-view event in Houston since he would not be able to make it to the live event in Beaumont, Texas.
But early Sunday, two co-workers received a series of text messages from the cell phones of Benoit and his wife. Most stated his home address in Fayetteville, about 20 miles south of Atlanta. One message from Benoit's phone said: "The dogs are in the enclosed pool area. Garage side door is open," according to WWE.
The text messages led WWE to ask authorities to check on Benoit and his family.
Ballard said the messages appeared to be an attempt by Benoit to get someone to the home to find the bodies after his suicide.
The prosecutor said it appeared the wrestler remained in the house for up to a day with the bodies.
The boy had old needle marks in his arms, Ballard said. He said he had been told the parents considered him undersized and had given him growth hormones.
"The boy was very small, even dwarfed," Ballard said.
Toxicology test results may not be available for weeks or even months, Ballard said. As for whether steroids played a role in the crime, he said: "We don't know yet. That's one of the things we'll be looking at."
Benoit received drug deliveries from a Florida business that sold steroids, human growth hormone and testosterone on the Internet, according to the Albany County, N.Y., District Attorney's Office, which is investigating the business, MedXLife.com.
Six people, including two of the pharmacy's owners, have pleaded guilty in the investigation, and 20 more have been arrested, including doctors and pharmacists.
Steroids have been linked to the deaths of several professional wrestlers in recent years. Eddie Guerrero, one of Benoit's best friends, died in 2005 from heart failure linked to long-term steroid use.
The father of Curt "Mr. Perfect" Hennig blamed steroids and painkillers for Hennig's drug overdose death in 2003. Davey Boy Smith, the "British Bulldog," died in 2002 from heart failure that a coroner said was probably caused by steroids.