As the police investigation into the murder of Ronan Kerr gets underway there will be a series of other parallel inquiries also beginning to find out how and why the 25 year-old lost his life.
It is just six weeks since Chief Constable Matt Baggott announced that the PSNI would receive an extra £245m to fight the threat from dissidents.
``The money will be spent on investigation, on more detectives, on more equipment, transport, air support, in sustaining our street presence in neighbourhoods,’’ he said.
It is a cruel irony that one of the first things that additional financial funding will be used for will be the investigation into the 25 year-old’s murder.
Security chiefs will be looking to see how and why the attack was not prevented, how it slipped through the net.
There will be questions for MI5, who have been in charge of targeting the dissidents since 2007.
Had police or the security services any prior warning that an attack was due to take place?
In recent months the security services on both sides of the border have managed to successfully thwart the vast majority of dissident attacks, with significant arrests including a key bomb maker from Dublin.
Was there any prior warning that Omagh was being targeted? Had there been any prior intelligence that Ronan Kerr’s life was under threat?
Police have a system in place in which officers are warned by text and email if there is intelligence that dissidents are planning an attack on area or individual. Was there a warning this time?
There will be questions being asked at MI5 headquarters in Holywood, Co Down but also at GCHQ in Cheltenham, where the intelligence agencies are said to monitor every telephone and text conversation which takes place in Northern Ireland.
The Special Reconnaissance Regiment (SRR), which was deployed into Northern Ireland in March 2009 to mount surveillance operations against dissidents, will also be facing hard questions as to how it missed the planning that went into the attack.
Police will be looking at the very real possibility that at least one of those who killed Ronan Kerr may have personally known the young policeman.
Someone will have provided the bombers with Ronan Kerr’s personal details. As the policeman’s mother, Nuala said on Sunday evening: “Someone knows something.”
There will also be questions about the potential threat which other officers living in quiet middle-class towns and villages now face.
The 25 year-old was not living in Ardoyne, Lurgan or the Bogside, where the threat to his life would have been more obvious.
This was Omagh.
A town where Catholics and Protestants can live side by side and which had escaped the worst of the Troubles until the Real IRA atrocity in August 1998.
Just weeks before his murder Ronan Kerr told friends that he felt safe living in Omagh despite having joined the PSNI.
He had celebrated St Patrick’s Day with friends in his hometown and talked about getting re-involved in local GAA.
He was already playing for the PSNI’s GAA team.
The 25 year-old’s decision to carry on living in Omagh after joining the PSNI would have had to have been approved by his superiors.
Police chiefs will now have to review how many other officers living in the same sleepy towns and villages may now also be under threat.
It will not have been lost on security chiefs that the bombers chose Omagh as their target.
In taking another life in Omagh the bombers have sent out a message that nothing is sacred.
It is another twisted irony that the only police officers which the dissidents have succeeded in killing and seriously injuring have been Catholics.
The CIRA gunmen who murdered Constable Stephen Carroll in March 2009 could not have known they were killing a fellow Catholic.
However the bombers who planted a device under the car of Peadar Heffron in January 2010 must have known his religion and that he was a fellow nationalist and an Irish speaker.
Similarly Ronan Kerr’s killers are also likely to have known that he was a Catholic and nationalist.
There was a poignant minute’s silence in memory of the 25 year-old as Tyrone and Kildare played a GAA league match on Sunday.
The game was due to have been played in Omagh but was transferred to Dungannon after constable Kerr’s murder.
A key concern of security chiefs will be the fact that, so far, no one dissident organisation has claimed responsibility for the murder.
In other attacks and murders rival dissident groups have fought out a macabre tug-of-war to be the first to claim responsibility, as some bloodied badge of honour.
But by claiming responsibility police and MI5 are quickly able to hone in on potential suspects.
Security chiefs will be particularly concerned to assure themselves that no new dissident group is about to announce its introduction on the stage of Irish republicanism by claiming the murder of Ronan Kerr.
There are already three main dissident groups, Real IRA, Continuity IRA and Oglaigh Na hEireann.
However there are a sizable number of former IRA members in east Tyrone who are publicly opposed to the Sinn Fein leadership.
There have been increasingly bitter recriminations between the two groups in Tyrone over the last 18 months and security chiefs will be anxious to assure themselves that this group, which has experienced bomb makers in its ranks, has not now become active.
Police will be keen to learn what type of device was used to kill Ronan Kerr.
The 25 year-old is understood to have been seriously injured when he opened the door of his car and the device either detonated or fell to the ground.
If correct, this would suggest the device was some type of grenade and not a new undercar bobby trap device. There has been speculation that dissidents have recently come into the possession of commercial explosives sourced in Europe. However, dissidents have used grenades before to attacked police. A “military-style” grenade was used in an attack on a police patrol in West Belfast last November.
It is no accident that the policeman’s murder comes five weeks ahead of the Assembly elections.
Republicans opposed to Sinn Fein will stand a number of candidates but it is unclear what political damage, if any, they will do to the Adams/McGuinness leadership.
While the dissident threat will be discussed in minute detail in newspaper columns and on radio programmes over the coming days and weeks, inside the various groups there continues to be upheaval.
There have been serious divisions within Maghaberry Prison recently with the dissidents’ OC (Officer in Command) being among three prisoners to leave the republican wing in recent weeks because of internal disputes.
Security sources claim that in Belfast only ONH appear to be capable of mounting attacks.
Recent hopes that representatives of the four main churches would agree to meet representatives of the main dissident groups appear to have been stalled indefinitely.
Ironically, the dissidents most serious weakness of lacking a co-ordinated leadership now appears to be their biggest strength.
At the height of the PIRA’s campaign the security services were able to closely monitor its activities because of the tight control which the central leadership maintained on its members.
It is highly likely that the first the dissident leadership knew of the attack on Ronan Kerr was through the media.