Philip Cairns' house.

Philip Cairns' route.

This is the route that Cairns was supposed to take that day. At the time of his disappearance, he had only recently started secondary school.

As you can see, the lane where his schoolbag was discovered is very close to his home on Ballyroan Road. It is about 450 meters away, which is a 2–5 minute walk.

The laneway where his schoolbag was found.

This is the lane where his schoolbag was found. It is about 100 meters long and connects Anne Devlin Drive with Anne Devlin Road.

Cairns' schoolbag was discovered six days after he went missing. It is believed that someone placed the bag in the alley at a later date, as it was dry despite recent rainfall.

Coordinates: 53.291220, -6.304540

Google Maps link.

His house in the 1980s.

This photograph shows what the house looked like on the day that he went missing. The garage with the orange door no longer exists. In 2012, it was converted into an extension.

Volunteers.

Volunteers searched for the 13-year-old in the foothills of the Dublin Mountains.

Gardai.

Following Cairns' disappearance, the Irish police canvassed the area by stopping motorists and showing them his photograph.

At the start of the investigation, there were reports that a woman in Tipperary had picked up a child matching his description. The boy claimed that he was from Waterford and that he had spent the previous night sleeping in a guest house. Unfortunately, this turned out to be a false lead.

Ballyroan Road.

That afternoon, he would have walked down Ballyroan Road.

2009.

This Google Street View image of the property was taken in 2009. This was before the garage was converted into a pitched roof extension.

Schoolbag.

This colorized photograph shows a member of the Irish police kneeling down beside Cairns' schoolbag. The bag was missing two religion books and a geography book.

Eamonn Cooke.

In 2016, a woman contacted the police and told them that she believed Cairns had been murdered by a former pirate radio DJ and convicted pedophile called Eamonn Cooke.

The woman, who was a victim of Cooke, was so terrified of him that she didn't come forward until she learned that he was dying.

According to the woman, she was in Cooke's car when they picked the 13-year-old up and drove to the DJ's pirate radio station at 58 Inchicore Road in Kilmainham.

At the time, she was just nine years old.

While they were at the studio, some kind of argument broke out, and Cooke hit Cairns over the head with an object.

When the incident occurred, she became upset and left the room. However, she later returned and saw the young boy lying on the floor.

After seeing blood, she reportedly fainted. Later, when she came to, she realized that she was in the back of Cooke's car and that Cairns was gone.

Cooke confirmed parts of the woman's story to detectives. However, at the time, he was receiving palliative care and suffering from dementia. Furthermore, he did not reveal the location of Cairns' remains.

Cooke died just as investigators believed that he was finally going to confess.

Although he was suffering from dementia, suspicions about his involvement were strengthened after he replied with key details to an open-ended question. Notably, many of these details matched up with what the woman had said.

DNA.

Investigators were able to retrieve "touch DNA" from the schoolbag using new technology. However, testing failed to link it with Cooke or any other person of interest.

It is hoped that this DNA will one day uncover the identity of the person who placed the bag in the laneway.