The former Irish Republican Army (IRA) commander Gerard Davison, also known as "Jock," was shot dead outside of his home on Tuesday at about 09:00 BST, in the Markets area of Belfast.
The body of Davison lay outside his home on the street until police covered him with a sheet and collected forensic evidence.
No one has claimed responsibility for the killing of Davison, who was shot at least once behind the head in front of children going to school.
However, there are claims Davison that was linked to the killing of Robert McCartney in 2005.
According to police and court testimonies Davison was the Belfast IRA commander that ordered the killing of McCartney, who was beaten and stabbed to death outside Magennis pub in 2005.
In 2005 Davison was detained on allegations of ordering McCartney to be killed by IRA comrades, as McCartney’s sister claimed the former IRA commander made a throat-slashing gesture to IRA colleagues.
Davison was later released without, however his Uncle Terence Davison and another person were charged with murder but later acquitted in 2008.
Police have called on witnesses to come forward and Sinn Fein President Gerry Adams condemned the murder.
Sinn Fein is an Irish Republican political party which originated from the Sinn Fein organisation in 1905 established by Arthur Griffith. The party split in 1970 and is well known for its association with the IRA. Sinn Fein is active in both Ireland and Northern Ireland.
Gerry Adams, who has been the party’s president since 1983, said “This brutal act will be condemned by all sensible people - there can be no place for such actions. I would urge anyone with any information to bring that forward to the PSNI.”
Davison wasthe first pro-peace process senior republican killed since the ceasefire declared by IRA in 1997.
The day before Davison was killed, police in Northern Ireland have confirmed that two bombs were discovered and partially exploded near an army reserve base just 20 metres away from residential buildings in Londonderry.
The latest incident is the third bombing incident in Northern Ireland targeting security officials in a week.
The area where the bombs partially exploded is populated with many elderly people, including some suffering alzheimer's. Police evacuated 15 homes during an operation held on Monday night.
Police Service of Northern Ireland (PSNI) chief inspector Tony Callaghan condemned the attack and stated that the bombs could have easily harmed someone as they were “clearly designed to kill or seriously injure.”
Callaghan also said, “It was absolutely reckless for someone to leave these devices at the perimeter fence line of an Army reserve base in such close proximity to a number of properties.”
No one has claimed responsibility, however, the Irish Republican Army (IRA) has been accused of two previous bombing incidents in the past week.
On April 27, a bomb exploded outside a probation office in Londonderry and on May 1 another exploded outside a police station in Belfast, the capital of Northern Ireland.
Both bombing incidents have been evaluated as IRA-style bombings by security officials and have raised alarms in the country as they are now the third attack against the police and military in just over a week.
The IRA was established in 1969 and fights in favour of the ideology of Irish Republicanism (uniting Northern Ireland with the Republic of Ireland) and is well known for involvement in criminal activities such as bombings, assassinations, smuggling and robberies.
The group highly condemns sectarianism and sectarian attacks, despite its members being involved in the killing of many protestants and catholics during the periods of 1975-1976, including the Kingsmill massacre.
Tension inside the group led to splintering and when the Provisional IRA declared ceasefire in 1997, the New IRA came into being.
The New IRA sticks to the ideology that Northern Ireland should be united with the south and continues to undertake violent attacks, generally targeting soldiers and police officers.
In March 2009, the IRA targeted an engineer regiment in Antrim town, Northern Ireland, killing two British soldiers and injuring four others.
Just two days after the killing of the two soldiers Police Constable Stephen Carroll was killed in Craigavon, Northern Ireland.
Tension between police and the IRA peaked when the group allegedly tried to bomb a hotel in Londonderry in May 2014 which was meant to host a police recruitment fair.