FAYETTEVILLE, Ga. — The Fayette County Sheriff's Office closed its investigation of the killings at pro wrestler Chris Benoit's home last June.

The department said in a statement Tuesday that investigators stand by the initial conclusion that Benoit killed his wife and 7-year-old son and then himself in their suburban Atlanta home.

The statement said there is no evidence "that indicates the presence of any other individual or individuals who contributed to the deaths of the three members of the Benoit family."

Authorities have said Benoit, 40, strangled his wife with a cord, used a choke hold to strangle his son, placed Bibles next to the bodies and hanged himself on a piece of exercise equipment the weekend of June 22, 2007, in their Fayetteville home.

A medical examiner was unable to say if steroids played a role in the killings, though suspicions linking steroid use to the killings have lingered. Anabolic steroids were found in Benoit's home and tests showed Benoit had roughly 10 times the normal level of testosterone in his system.

Benoit's personal doctor, Phil Astin, faces federal charges of improperly prescribing medication to two patients other than Benoit. More charges are expected.

Authorities have said Astin prescribed a 10-month supply of anabolic steroids to Benoit every three to four weeks for a year leading up to the killings.