With the Haass discussions failing to find agreement, the HET is still the main route for families to find answers. However, the problem is its credibility after a damning report published last year exposed serious failures in how it operates.
How to deal with the legacy of the Troubles is one of the areas where progress was made during the Haass talks.
Next week, the parties will return to Stormont to deal with the proposals contained in the seventh draft of the process independently chaired by former US diplomat Dr Richard Haass, along with his co-chair and international affairs expert Professor Meghan O'Sullivan.
The proposals would see the Historical Enquiries Team replaced by a new unit with new powers.
Dr Haass also envisaged a commission where anyone giving evidence would be able to tell whatever they knew in return for limited immunity.
But, without political agreement that is all on hold and the HET has now found itself back in the spotlight.
During a debate about the Haass talks, DUP MP Ian Paisley Jnr pushed the Secretary of State over the cost of policing the past and present - challenging her to financially commit to the structures already in place.
"How would the Secretary of State try to fund such a unit with it's panoply of lawyers and additional experts when there is a shortfall of £60m starting in 2015 for the current arrangement which is the cheaper option, and when there is another shortfall of an additional £36m generally on security?"
He queried: "Will the Secretary of State commit now to finding the money to allow the police to function for the next five years rather than pursue this fanciful idea of an Historical Investigations Unit."
Theresa Villiers responded that he was right to raise the cost.
"That is something that would need to be resolved in the event of an agreement, as I've said, the UK government would primarily expect the Northern Ireland Executive to fund that from within the considerable resources provided by the block grant.
"We'll obviously consider any application for a top up funding to that but when we have to deal with a deficit of the gravity that we do, it does make it difficult to commit to additional funds at this stage."
Eight years ago, the painstaking process began of re-examining over 3,000 killings carried out during the Troubles.
The recent conviction of IRA man Seamus Kearney more than three decades after a fatal shooting is an example of how the HET is supposed to work at its best.
Justice finally caught up with the 54-year-old from Swatragh, Co Londonderry after his DNA was found on a cigarette butt left at the scene where Constable John Proctor was shot dead.
The policeman was murdered just minutes after visiting his wife June and new-born son at the Mid Ulster Hospital on 14 September 1981.
Speaking after the court case in November, Mr Proctor's widow said that getting a conviction in a court was her ultimate desire.
"It was like a weight had been lifted off my shoulders - finally we got justice."
However, not many cases have made it to the courts as a direct result of HET investigations. The passage of time - and the loss of vital evidence - made that impossible in many cases.
Confidence in the HET took a battering - and its very existence was thrown into doubt - when last year, the UK's top policing watchdog exposed serious flaws in how it works.
Her Majesty's Inspectorate of Constabulary found that the team treated army killings very differently to any other on its books - and in fact, acted illegally.
Many families who put their trust in the HET felt disillusioned and betrayed.
Margaret Kennedy's mother and aunt were killed by the army in 1971.
Speaking when the report was published last year, she said: "I feel really hurt, I feel angry, because when you think you're getting so far, and then for a report like that to come out today, and you're just re-living the whole emotional upset of it, you're just re-living everything."
The controversy put the future of the HET in jeopardy and the PSNI, who oversee it, had to put new management and structures in place.
It is still not enough for everyone, but for now in the absence of political agreement on Haass, it is still the main way of re-examining the past.