LONDON — Britain’s government said Monday that it has decided against holding a public inquiry into the murder more than three decades ago of a Belfast attorney who specialized in defending Irish Republican Army suspects.

Patrick Finucane, a 39-year-old attorney, was shot 14 times at his Belfast home by gunmen from the paramilitary group Ulster Defense Association in February 1989. His family has campaigned for years for a public inquiry into allegations that Northern Ireland police and the British army colluded with the killers.

Several investigations have concluded that there was state collusion in Finucane’s murder, and the British government has apologized to the family. But last year, the Supreme Court said that all previous examinations into the death were inadequate.

Northern Ireland Secretary Brandon Lewis said he met the Finucane family on Monday and told them authorities decided “not to establish a public inquiry at this time.” He added that this was because investigations by Northern Irish police and the police ombudsman needed to finish first.

Finucane’s son, John, said the British government’s announcement was “nothing short of insulting” after the family waited three decades for an effective investigation into their father’s murder.

“The British government at every opportunity will continue to make the wrong decision and put all their efforts into ensuring that the truth of what happened to my father will not see the light of day and they are intent on suppressing that,” he said.

Lawmaker Tony Lloyd, with the opposition Labour party, said “it was collusion by agents of the state and … we still need to find out how far that collusion went.”