Georgia's assisted suicide statute, unlike such laws in about three dozen other states, does not actually make it illegal to help someone to die, Rubin said.
The law (O.C.G.A. 16-5-5) says anyone who "publicly advertises, offers, or holds himself or herself out as offering" to assist with a suicide is guilty of a felony.
In effect, said Rubin, the law prohibits speaking about assisted suicide. And that, he said, is a violation of the First Amendment right to free speech.
"It's a really weird statute," Rubin said. "To me, it doesn't even seem like a close call. But we'll see."
Assisting a suicide is punishable by up to five years in prison. Tampering with evidence carries a maximum sentence of 10 years in prison, and a racketeering conviction could bring up to 20 years in prison.
Celmer's death, and the planned assisted death of an agent from the Georgia Bureau of Investigation, were the basis for the racketeering charge, according to prosecutors.
Authorities have said the network has helped others kill themselves since it was founded in 2004.
Egbert, also a co-founder of the network, was the group's medical director. He has said that he signed off on more than 200 death requests, including those of Celmer and of the GBI agent, before he and the other three were arrested early last year.
The four defendants have been free on bond. Their arrests sparked a spirited debate about the morality and legality of assisted suicide in Georgia.
On its Web site, the Final Exit Network promotes "our right to die a peaceful and painless death at the time and place of our choosing."
The group's members maintain that they thoroughly screen those seeking help "hastening" their deaths, and that only those who have incurable illnesses are accepted and issued an instruction book.
The process, according to authorities, works like this: A tank of helium and a plastic hood lead to death by suffocation, and the gas escapes, leaving no evidence that the death was intentional. An "exit guide" who is at the death bed offers emotional support and then removes the tank and any other evidence of suicide, leading family members and authorities to suspect the death was natural.
That pattern was repeated in Celmer's death, according to authorities.
Though Celmer had cancer, his doctor has said he was not dying. Still, his death was initially blamed on health issues.
But in his Cumming townhouse, his family found information about the Final Exit Network and notes of conversations Celmer had with at least one network member about "coordinating my demise."
They also found a receipt for two tanks of helium bought a few weeks before his death, according to an affidavit for the arrest warrant.
The affidavit also noted that Celmer was concerned about his appearance after surgeries to repair his deteriorated jaw.
An investigation was opened, and a GBI agent, posing as a Dawson County man dying of pancreatic cancer, sought the Final Exit Network's help.
According to the charges, Goodwin walked the undercover agent through the steps that would have killed him. Goodwin, authorities say, demonstrated how he would hold down the agent's hands to prohibit him from removing the "exit bag." That's when other agents arrested Goodwin, according to the GBI.
Blehr, an "exit guide, " was to have been there as well, but she had a car accident on the way and was detained, authorities say.