When it comes to the past in Northern Ireland, nothing seems to shock any more.
Is it because we’ve become so used to accepting certain things, like the unpalatable truth?
But none of that takes away from the sobering reality of the latest report just published by the Police Ombudsman.
That investigation focused on how police dealt with a deadly threat from the UDA/UFF in the north west.
Almost 20 murders in the space of just four years - including the Greysteel Massacre. As well as indiscriminate killings, there was the specific targeting of republicans, Sinn Fein councillors and members of the IRA.
And by the end of it all police did get more of a handle on that loyalist threat. But it came at a terrible cost.
“The protection of informants and the protection of sources by RUC special was seen as a priority in some instances the risks to the public,’’ says Police Ombudsman Marie Anderson.
The use of informers, spies, whatever you want to call them, a key tool in the fight against terror.
Be that 30 years ago against loyalist and republican paramilitaries or in today’s world.
But they have to be carefully managed.
And in a number of high-profile attacks here, they weren’t, including this one.
“I understand why police engage, recruit, use, informants. I think that is an important policing tactic that can help infiltrate gangs, republican and loyalist paramilitaries. But where I consider a red line to be drawn is the the specific use of two informers in this case where there was evidence and intelligence they were involved in murder,’’ says Ms Anderson
“That is entirely against Northern Ireland guidelines and police policy...
“I talk about this, rewards and risks. Using an informant that's part of a terrorist gang. You can see that it can bring rewards by way of timely quality intelligence and information that could lead to those gangs’ plans being disrupted and potentially saving lives…
“There are risks though. These are individuals which some of the Special Branch handlers have described as lowlifes and they knew they were accomplished liars…"
Back in 1988, before the first murder, intel came in that the UDA/UFF was waiting the arrival of a shipment of weapons from South Africa.
We already know that shipment was organised by the now dead army agent Brian Nelson.
Some weapons were recovered, but others ended up in the hands of the different loyalist paramilitaries groups including the UDA/UFF in the north/west.
Now, the ombudsman is clear, there’s no evidence police had any prior knowledge of these attacks.
But by the time the RUC caught on to that emerging threat by loyalists in the north west, they were already playing catch up.
I asked the ombudsman did the failure to initially tackle that emerging threat, provide that group with an opportunity to arm itself to become a murder machine?
Her reply: “Indeed, and that's one of the reasons that's included in the Operation Greenwich series."
So much more is in this report. Deaths threats not passed on to those who were later murdered, including two Sinn Fein councillors.
Once again raised, the close links some police officers and members of the military had with loyalist paramilitaries back then.
“Passing information to loyalist gangs with a view to targeting individuals, that was unacceptable then and is unacceptable now," says Marie Anderson.
The RUC is no more and policing has been transformed.
Difficult perhaps for senior officers now in today’s world to say sorry for damning failures that didn’t happen on their watch.
And with more of these reports due in the coming weeks, there may be more.