A former Irish Republican Army commander linked to one of the outlawed group's most notorious killings was shot dead at close range Tuesday morning on a street near his home in Belfast, residents and police said.

No group claimed responsibility for killing Gerard "Jock" Davison, 47, in Belfast's Markets neighborhood in what was the first fatal shooting in Northern Ireland in more than a year.

Police said it was too early to speculate on a motive.

But officers ordered an immediate increase in visible street patrolling, including road checkpoints, to deter what they called a rise in attacks by IRA die-hards who oppose British rule in the run-up to Thursday's United Kingdom general election. Northern Ireland elects 18 members to the House of Commons in London.

"This was a cold-blooded murder carried out in broad daylight in a residential area and it has no place in the new Northern Ireland," said the policeman leading the investigation, Det. Chief Inspector Justyn Galloway.

The relative rarity of Tuesday's killing did underline how much has changed in Northern Ireland from the bloodiest years of its four-decade conflict that left more than 3,600 dead.

IRA supporters who long boycotted contact with police appealed Tuesday to the predominantly Catholic residents of the Markets to tell detectives what they knew about the killing.

That latter change contains bitter irony for Davison, who once presided over the Markets wielding an IRA authority that included, for decades, the right to shoot criminal opponents in the limbs and to shield its own members from British law and order -- including by killing those who would tell the police what they knew.

Davison was a Belfast IRA commander in 2005 when he allegedly ordered IRA comrades to attack a man, Robert McCartney, at a pub near the Markets following an exchange of insults. Nobody was ever successfully prosecuted for the fatal stabbing, which happened in front of dozens of witnesses, amid claims of IRA intimidation.

Defying the IRA's code of silence, McCartney's widow, his mother and four sisters took their demands for justice all the way to the White House, winning support from Hillary Clinton and the late Sen. Edward Kennedy. Their unprecedented campaign helped spur the dominant IRA branch, the Provisionals, to renounce violence and disarm later that year.

McCartney's sisters accused Davison of making a throat-slashing gesture to his IRA colleagues before McCartney, 33, was chased outside the pub and killed. IRA members confiscated the pub's surveillance video footage, cleaned up forensic evidence and ordered pub-goers to tell police nothing or risk IRA retaliation, according to police and court testimony.

Davison was arrested on suspicion of ordering the killing but not charged. Two others, including his uncle Terence Davison, were charged with McCartney's murder but acquitted in 2008.

IRA representatives met McCartney's widow and sisters and offered to have the IRA members responsible killed as punishment, an offer the women rejected. The IRA and its allied Sinn Fein party later announced they had expelled or suspended three IRA members and eight Sinn Fein members over their alleged role in the assault on McCartney and the cover-up of evidence.

Gerard Davison always denied involvement in the McCartney attack, insisting he tried to act as a peacemaker when McCartney and McCartney's friend Brendan Devine got into an argument inside the pub with Davison's uncle and some IRA members at his table.

Davison's body lay in the street Tuesday until police constructed a tent around the victim to protect forensic evidence. Residents said at least some of Davison's three children saw their father lying dead and ran home screaming.

Sinn Fein official Alex Maskey said his party wouldn't speculate on who killed Davison or why. He called Davison "a longstanding republican" who was "very well regarded."

The Provisional IRA is observing a 1997 cease-fire in support of Northern Ireland's peace process after killing nearly 1,800 people in a failed effort to force the British territory out of the U.K. and into the Republic of Ireland. But splinter groups continue to mount bombings and shootings, and feuds within the IRA's fractured ranks can turn deadly.