ATLANTA (CNN) — Georgia’s Supreme Court on Monday unanimously struck down the state’s assisted suicide law, a decision that results in the dismissal of criminal charges against four members of an assisted suicide network.

The law is “unconstitutional under the free speech provisions of the United States and Georgia constitutions,” wrote Justice Hugh Thompson in the court’s opinion. The court said that a ban on assisted suicide could be constitutional, but the way the Georgia law was written made it unacceptable. The law targeted only those who publicly offer to assist in suicide.

The 7-0 ruling reverses a lower court’s finding that the Georgia law was constitutional and its denial of a motion by the four requesting that charges against them be dismissed.

Clare Blehr of Atlanta; Thomas Goodwin of Punta Gorda, Florida, and the Atlanta suburb of Kennesaw, Georgia; and Dr. Lawrence D. Egbert and Nicholas Alec Sheridan, both of Baltimore, were arrested in February 2009 as part of an investigation into the Final Exit Network.

The four were accused of helping John Celmer, 58, of the Atlanta suburb of Cumming end his life in June 2008. Celmer suffered from severe mouth and throat cancer, his mother, Betty Celmer of East Amherst, New York, told CNN in 2009.

All four were indicted in March 2010 on charges of offering to assist in commission of suicide; tampering with evidence; and violation of the Georgia Racketeer Influenced and Corrupt Organization Act, according to a Supreme Court summary of the case.

Final Exit, which lists a New Jersey address on its website, was incorporated in Georgia, according to the Supreme Court. It describes itself as “an all-volunteer organization serving members in all 50 states who are suffering from intolerable medical circumstances and want to end their lives.”

According to briefs filed in the case, Celmer contacted Sheridan, the Southeast regional coordinator for the Final Exit Network, in May 2008, sending him medical records and a statement that he wished to end his life, the court’s summary said. Celmer was assigned a “first responder,” who completed a questionnaire with him.

The results of the survey and Celmer’s medical records were forwarded to Goodwin, then the organization’s president, who approved him for assistance, according to court documents. Blehr was assigned as Celmer’s “exit guide.”

Celmer ordered an “exit hood” and bought two tanks of helium, the court said. In June 2008, prosecutors alleged, Blehr and Goodwin went to Celmer’s home to assist in his suicide. The exit hood was connected to one of the tanks and placed on Celmer’s head. Blehr and Goodwin held the man’s hands as he died, according to court documents.

The four were arrested after the Georgia Bureau of Investigation set up a sting operation, with an undercover agent posing as a terminally ill man seeking assistance with his suicide.

As the “suicide” was set to take place, Goodwin walked the agent through the steps and demonstrated how he would hold the agent’s hands to stop him from removing the “exit bag,” GBI spokesman John Bankhead said at the time.

After death occurs, the GBI alleged, “all evidence is removed from the scene by the ‘guides’ and discarded, as evidence indicated happened in the Cumming case.” Prosecutors claimed Blehr and Goodwin disposed of the hood and helium tanks in a trash bin, according to the court summary of the case.

The Georgia Supreme Court ruling notes that Georgia’s law did not ban assistance in all suicides. The state argued the law is “narrowly tailored because it reaches only those who publicly offer to assist in suicide and then, in fact, undertake an overt act to accomplish that goal,” the ruling said.

Attorneys for the state said the statue was intended to criminalize assisted suicide in some instances — particularly “for the purpose of preventing a ‘Dr. Kevorkian type actor’ from offering to assist suicide while leaving others free to do so,” the ruling said, adding that it does not apply to those who do not publicly offer to assist in the commission of a suicide.

The state said the law’s restriction on free speech was justified by the state’s “compelling interest in preventing suicides,” the ruling said.

“Had the state truly been interested in the preservation of human life, however, it could have imposed a ban on all assisted suicides with no restriction on protected speech whatsoever,” Thompson wrote. “Alternatively, the state could have sought to prohibit all offers to assist in suicide when accompanied by an overt act. … The state here did neither.”

“The state has failed to provide any explanation or evidence as to why a public advertisement or offer to assist in an otherwise legal activity is sufficiently problematic to justify an intrusion on protected speech rights,” the opinion said.

— CNN’s Vivian Kuo contributed to this report.