Detectives investigating the mysterious death of Noah Donohoe are gradually piecing together the tragic teen's final moments and know where he entered the north Belfast storm drain complex where his body was found yesterday.
As officers continue to scour CCTV footage and trawl through data on his laptop, they don't believe there was any crime involved in the 14-year-old's death.
But they are still trying to discover why exactly he entered the underground drains.
His remains were discovered in the pitch dark storm drain complex in the Shore Road area yesterday morning, leaving his family and friends devastated after almost a week of searching.
Noah had cycled from his home in the Ormeau Road area in south Belfast to the north of the city early last Sunday evening.
Local sources said his body was found at around 9.45am in a network of underground drains close to the Shore Road. The drains cover an area of almost one kilometre.
It is not known how police have established where he entered the drains but they have been examining CCTV in the area over the past two days.
One line of inquiry is believed to be that Noah - a year 10 pupil at St Malachy's College in north Belfast - either entered the storm drain for shelter on the Sunday evening of his disappearance, or that he was concussed and confused following an earlier fall.
PSNI Superintendent Muir Clark said the specialist search teams deployed to search the drains found it "extremely challenging".
Superintendent Clark added the location Noah was found is "very different" to where he entered and that they were "very confident" they knew his point of entry.
He said: "We did have access to the storm drain complex and it has been searched over the last number of days before we got to the end of the complex.
"It's an extremely challenging environment in which to work and that is why it has taken the length of time to go through that complex.
"They were working in the pitch black and there was a lot of ground to cover.
"In my 30 years in the police, this is one of the most unusual missing person inquiries that I have dealt with."
Superintendent Clarke also appealed to the public to refrain from posting rumours about the teenager online and insisted there was no indication of any foul play.
He added: "It is disappointing that I again need to comment about people circulating a number of rumours about Noah's disappearance, which are completely without foundation.
"This type of commentary and rumour is distressing for Noah's family and is extremely unhelpful.
"An investigation into the circumstances of Noah's disappearance is still continuing but there is no evidence to suggest foul play.
"If people post distasteful and patently untrue rumours on social media, we will investigate that."
On Friday officers discovered a bag containing a copy of the book 12 Rules for Life by Canadian psychology professor Jordan Peterson and the teenager's Lenovo laptop, which is being examined by specialist officers and continues to form a key part of inquiries.
"We're continuing to examine the electronic equipment which we have recovered and obviously that forms part of the investigation into the disappearance of Noah.
"In any electronic device there are massive amounts of information so we continue to sift through that information just to build the picture.
"There will be a post-mortem examination which will be conducted and that will very much, hopefully, give some answers."
He also said that shorts and a coat belonging to Noah are still missing.
Detectives say they believe Noah may have fallen from his bike on Sunday evening and hit his head before stripping off naked and then continuing to to cycle through the city based on witness statements.
It is believed he may have suffered concussion as a result of the fall.
The Donohoe family was left devastated yesterday morning when the PSNI informed mum Fiona that her son's body had been discovered.
Close relatives last night declared the tragic teenager would remain "forever in our hearts".
Cousins Darcie and Shaneane Donohoe both posted tributes on social media to their 14-year-old cousin. "We love you forever Noah," wrote heartbroken Shaneane while Darcie said: "Forever in our hearts."
A vigil is due to take place in Fiona's hometown of Strabane tonight at 6pm at 'the Tinnies' sculptures.
A huge search operation had been mounted last week with hundreds of people helping police and specialist teams look for the youngster.
As news of his death broke yesterday, there was an outpouring of sympathy for the boy and his family.
Belfast boxing legend Carl Frampton said: "It's just awful to hear the news about Noah.
"I had been searching his name every day to see the latest news on the search for him - it's a story that has touched everyone.
"To his mum and the wider circle I extend my deepest condolence."
North Belfast MP John Finucane said: "This is tragic and heartbreaking news for his family and friends and all who knew him as well as the entire community who were involved in the search for him."
Belfast Lord Mayor, Alderman Frank McCoubrey, also expressed his deepest condolences to the family.
He added: "I was so deeply saddened to hear the news about Noah and I know that I speak for the entire city in expressing condolences to Noah's family and friends.
"It is incredibly sad to see the loss of such a gifted and well-loved young man, and as a father myself, I cannot begin to imagine the anguish and pain at the loss of a child.
"I would like to pay tribute to the community of north Belfast who have come together, helping in the search for Noah, and also to the PSNI and Community Rescue Service who have worked tirelessly in recent days."
The disappearance of the teenager has captivated and mystified Northern Ireland since the boy vanished a week ago and officers failed to find any trace of him until yesterday.
Noah left his home in south Belfast at 5.30pm on Sunday and was seen on Ormeau Avenue, heading towards the city centre, 15 minutes later. He was then seen on Royal Avenue and York Street before he was again spotted at 5.57pm on North Queen Street. A few minutes later, a boy fitting Noah's description was seen falling from a bike around a quarter of a mile further up the road.
A final sighting of Noah was at 6.11pm when he was seen heading in the direction of Northwood Linear Park, a densely wooded area.