Dr. Phil Astin, Chris Benoit’s personal physician at the time he killed his family and hanged himself nearly one year ago, was charged on Thursday in a new 175-count federal indictment with conspiracy and improperly dispensing drugs.

The new indictment against Dr. Astin replaces a seven-count indictment last July and involves 17 additional patients.

As you will likely recall from events at the time of the shocking double murder-suicide, Astin was understood to have prescribed a 10-month supply of anabolic steroids to Benoit every three to four weeks for a year leading up to the killings.

The Atlanta Journal-Constitution reported on Thursday that patients allegedly received illegal prescriptions for Percocet, Oxycontin, Demerol, Lorcet, Ritalin, Vicodin, Xanax, Adderall and Soma from Astin.

The Associated Press on Thursday evening revealed that patients in the indictment were referred to in court papers by their initials. Prosecutors would not discuss the initials. However, two entries were initials similar to those of Benoit and his wife, Nancy.

Astin was initially charged with illegal distribution of prescription drugs to two patients other than Benoit. Those charges came after the June 2007 killings at Benoit’s home in Atlanta.

Authorities said Benoit, 40, strangled his wife with a cord, used a choke hold to strangle his seven-year-old son, placed Bibles next to the bodies and hanged himself on a piece of exercise equipment in their Fayetteville home.

Suspicions linking steroid use to the killings have lingered, since anabolic steroids were found in Benoit’s home and tests showed Benoit had roughly 10 times the normal level of testosterone in his system.

But despite the claims of some experts that “roid rage” was to blame, authorities have never publicly linked the Benoit killings to steroid use.

Benoit’s father believes years of head trauma his son suffered while in the ring contributed to the killings – a theory backed up by others including former WWE wrestler Christopher Nowinski, whose excellent Head Games: Football’s Concussion Crisis book examined the long-term effects of head trauma among athletes.

U.S. Attorney David Nahmias said on Thursday that the investigation is ongoing.