Three teenagers are facing life sentences after murdering a pensioner in his home.

Keirin McMillan, 19, and his two accomplices, who were aged 16 and 15 at the time, inflicted more than 100 injuries on Alasdair Forsyth after they entered his flat to rob him.

One of the teenagers later said in a phone call recorded at a young offenders' institution: "It was for money." He added: "We were all just out our nut."

Advocate depute Stewart Ronnie told jurors at the High Court in Edinburgh: "This was a brutal, sustained attack on a 67-year-old man in his own home, involving weapons and involving all three accused."

The trio had denied murdering Mr Forsyth on February 21 this year at his flat in the Prestonfield area of Edinburgh, but all were found guilty of the offence.

They repeatedly struck the victim on the head and body with a screwdriver, hammer, wrench, his walking stick and picture frames.

They also kicked and stamped on him and robbed him of a tablet device and a phone. One of the youths, who is under 18 and cannot be named for legal reasons, was freed on bail at Edinburgh Sheriff Court the previous month.

The two younger killers were also found guilty of committing further attacks at a McDonald's at Sharpdale Loan, in Edinburgh, and at the city's Cameron Toll shopping centre days before the murder.

The trial judge, Lord Uist, told them: "You have each been convicted by the jury of a scandalous murder."

"The penalty for murder is fixed by law. In the case of you, Keirin McMillan, it will be that you will be detained in a young offenders' institution and liable to be detained for life," he said.

He told the two younger killers that they would be detained without limit of time.

The judge said he could not pass sentence today because he required background reports on them before fixing the minimum terms they must serve before they become eligible to apply for parole.

Lord Uist told jurors after the youths were led off to cells that it had been "a very distressing case".

One woman told the trial that McMillan had come to her house before the fatal attack with tools in a bag.

"You have each been convicted by the jury of a scandalous murder."

Lord Uist

She said he had repeatedly talked about there being money in books in Mr Forsyth's home.

She said the 16-year-old had returned to her home "pretty wasted" and she asked McMillan if he had given him tablets, but he just laughed.

McMillan later revealed he had taken street Valium before the murder.

The three killers set off armed with weapons for Mr Forsyth's flat and emergency services were alerted because of a disturbance.

The first police officers on the scene went into the stairwell and could hear "excited" male voices coming down the stairs before they met the blood-stained, youthful killers.

McMillan later told police: "The blood on my cottons is from my nosebleed and the blood on my trainers is from what happened there." He did not appear to have a nose bleed.

McMillan said of the victim that he could "handle himself" and did not need a walking stick.

He later went on to claim that he had tried to act as a peacemaker and intervened to help the victim as he was attacked by the two younger killers using the hammer and screwdriver.

The youngest killer said to an officer: "Do you know who I am?" He squared up to the policeman in a fighting stance but was handcuffed. He later asked about his iPhone which he had lost.

Pathologists who examined the victim concluded that his death was caused by severe chest trauma, which was most likely because of the extensive rib fractures he suffered.

The victim sustained multiple broken ribs and extensive bruising and cuts in the fatal attack in his home.

All three youths were remanded in custody ahead of sentencing in January.