A federal judge has dismissed a lawsuit brought by a former state prison captain seeking to hold cellphone providers liable for an attempt on his life that was allegedly ordered by a vengeful inmate using a smuggled phone.

Attorneys for Robert Johnson and his wife Mary said they will appeal the June 27 decision by U.S. District Court Judge Cameron McGowan Currie.

“We respectfully disagree with the court,” said John Parker of Hampton, a lawyer representing the Johnsons.

“We strongly believe that ruling will adversely affect prison safety,” Parker said.

He said the providers can jam illegal cellphone use by inmates without interfering with other communication systems.

“A huge amount of crimes” would be prevented that way, he said.

The case next goes before the U.S. Court of Appeals for the Fourth Circuit in Richmond, Va., he said.

A ruling in favor of the plaintiffs could have a nationwide impact, Parker said.

The Johnsons sued 20 cellphone companies and cellular tower owners in connection with the attack, in which he was shot six times at his Sumter home. They allege that these companies had the ability to block inmate calls from Lee Correctional Institute in Bishopville, where Johnson worked.

For more than two years, South Carolina has been seeking federal permission to jam cellular signals at state prisons, but the request has stalled before the Federal Communications Commission, despite support from 30 other states.

Regulators have said that a 1934 law allows only federal agencies to jam public airwaves. And cellphone companies have argued that the jamming methods suggested by South Carolina and other states could interfere with emergency communications and other legal cellphone use.

Attorneys for the cellphone companies did not respond to requests for comment on Friday.

Clark Newsom, spokesman for the South Carolina Department of Corrections, said testing at Lieber Correctional Institute in Ridgeville showed that contraband phone-signal jamming does not interfere with other cellular service in the area.

However, because the issue seems to be at an impasse, the DOC has moved on and is exploring other ways to prevent the problem of phones smuggled into prison. Often, cellphones and other contraband are thrown over a prison fence, he said.

Meanwhile, the shooting of Johnson is working its way through the criminal courts.

Sean Echols, 29, of Orangeburg, is accused of trying to kill Johnson, 59, in exchange for $6,000 in cash, according to the U.S. Attorney’s Office.

As Johnson was preparing for work on March 5, 2010, a gunman broke down the front door of his home and blasted six rounds into Johnson’s chest and stomach in front of his wife.

Echols is charged with conspiring with unidentified accomplices to murder the former corrections captain. He also is charged with using facilities of interstate commerce in connection with the attempted murder, and with using and discharging a firearm in connection with a crime of violence.

Johnson has said investigators told him the conspiracy involved the shooter, a getaway driver and two inmates who orchestrated the hit. So far, only Echols has been charged.

Kathryn Richardson, spokeswoman for the State Law Enforcement Division, said the investigation of the crime is ongoing.

“It would be inappropriate for me to comment any further,” she said.