Several key pieces of evidence caught the teenager who murdered six-year-old Alesha MacPhail.

The 16-year-old was found guilty on Thursday of abducting, raping and murdering her on the Isle of Bute in July last year.

Throughout the trial, the jury listened to damming evidence which in the words of prosecutors was "mountain" high.

Here's how the Crown pieced together their case at the High Court in Glasgow.

A cybercrime expert told jurors the search was made on Google at 12.32am on July 3 last year, the day after the child's body was discovered.

He said the phone was then used to access a How Stuff Works article entitled: "Collecting DNA evidence".

The evidence came from cybercrime team leader Peter Benson.

It was contained in an 89-page report which was compiled after a forensic examination of an iPhone 6, said to belong to the accused.

The 16-year-old sent a selfie-style video to a Snapchat group with the message: "Found the guy who has done it."

Giving evidence, a friend of the accused said the post was sent hours after Alesha's body was discovered in a wooded area on the island.

She said it was posted to about 25 young people who were part of the Snapchat group.

The silent footage was shot in a bathroom and featured the top half of murderer's body but not his face.

The girl said: "He was saying what he thought happened and was questioning how she could've got out the house".

A second young witness also said he privately contacted her just three hours after Alesha was found dead.

She said: "During the conversation he started to get anxious and he said the police were going to blame it on him."

DNA of the boy was found on various parts of Alesha's body, including intimate areas, with 14 samples matching the accused.

Alesha suffered 117 injuries and died from significant pressure being applied to her face and neck.

DNA samples from the accused, his mother, Alesha's grandparents, her father and his girlfriend were taken for comparative purposes.

The jury was told various samples were taken from the child's body, with the murderer's DNA being detected on the front and back of Alesha's neck as well as her face.

The odds of it being from anyone else were more than one in a billion.

The mother of the killer contacted police after the child's body was found, a court has heard.

The teenage boy voluntarily spoke to officers at around 1am on July 3 at his home.

His mum had been drinking when she phoned Rothesay police station in the early hours of the morning after Alesha's body was discovered.

She told officers her son had been out of the house in the early hours of July 2, which was captured on CCTV.

The accused was described as "confident" and "very co-operative" by PC McKellar and asked his mum to leave the room while he spoke to officers.

A knife which was discovered on the beach opposite where Alesha MacPhail was last seen had the same design as those found in the accused's house, the trial heard.

Four knives from a block of five were found at the home of the 16-year-old boy who allegedly raped and murdered the six-year-old on the Isle of Bute in July.

The jury also heard a right palm print belonging to the teen was found on a chair rail at steps leading to the flat where Alesha was staying when she disappeared.

CCTV showed the 16-year-old leaving and returning to his homes several times on the night Alesha disappeared.

Footage was captured by a camera installed at the home because a relative with dementia was moving in.

It had been checked by his mum who wanted to see if she could spot any traces of Alesha.

Instead, the CCTV showed her son leaving and returning to the property on three occasions throughout the night.

A pair of jogging bottoms intertwined with a pair of boxer shorts were discovered on the shoreline near to where Alesha's body was found.

A black hoodie which was heavily salt stained was also discovered on the shore.