A gangland figure shot dead in a supermarket car park was "a maniac", a court has heard.
Steven Glen, 26, a former drug dealer, told a jury on Tuesday about a meeting he had with Kevin "Gerbil" Carroll moments before he was gunned down in broad daylight outside an Asda store in Robroyston, Glasgow.
He was giving evidence at the trial of Ross Monaghan, 30, who denies murdering Mr Carroll while acting with others on 13 January 2010.
Monaghan has lodged a special defence of incrimination, blaming others who cannot be named for legal reasons.
Mr Glen told the court he heard a few "cracks" and saw two masked men shooting into the Audi A3 Mr Carroll was in.
Monaghan's defence QC, Derek Ogg, asked him if he thought the Gerbil was "out of control?", to which he replied: "He was a maniac. I know that."
The court heard that Mr Carroll was trying to "move in" on other drug dealers and had told Mr Glen, an "independent", he would be working for him from then on during their conversation in the car park.
Mr Glen told the court a friend of his was "watching his back" from the supermarket cafe, as he was afraid he might be abducted by Mr Carroll.
Mr Ogg asked him: "Had you heard stories about the Gerbil torturing people, maiming and disfiguring people?"
He said: "Yes."
The QC went on: "About him digging out the tongues of people from their mouths?"
Mr Glen replied: "I hadn't heard that."
Mr Ogg said: "But you were absolutely terrified at the prospect of being abducted?"
The witness said: "Yes."
Mr Ogg put it to Mr Glen that he would have had more than one person "watching his back".
He said: "I just wanted someone to know what had happened to me if he took me away. There was no one I could have went to who could help me, who could fight with Gerbil. Nobody in the whole of Glasgow would f*** with him."
Mr Ogg said: "So it would seem your back was covered? A couple of angels were passing by looking out for a drug dealer who may be abducted by another drug dealer?"
Mr Glen said: "I took it that it was other people who were looking for him."
He agreed with Mr Ogg that it "looked bad" because there had been "no reprisals".
The court also heard that Mr Carroll characteristically travelled in the front passenger seat of any vehicle he was in. But on the day he was repeatedly shot by two masked gunmen, he was a passenger in the back of a three-door car.
Monaghan is also alleged to have attempted to defeat the ends of justice by concealing a revolver, a pistol and ammunition under bricks and undergrowth in Academy Street in Coatbridge, North Lanarkshire, and setting fire to a car.
He faces further charges of possessing firearms and ammunition without a proper certificate.
Mr Glen said Mr Carroll had allowed him to choose the time and place of their meeting.
He said Mr Carroll had told him "anyone who doesn't toe the line will be getting banged", which he took to mean they would be shot.
The court heard that Mr Glen made between £2,700 and £5,000 a week dealing cocaine and has a previous conviction for supplying heroin.
However, he only told Mr Carroll he was making about £2,700 by selling four-and-a-half ounces of cocaine a week. Mr Carroll told him "you'll be getting that from us now", the court heard.
When interviewed by police Mr Glen told officers that Mr Carroll had said to him: "You give me numbers for people who are doing gear, even people you don't want to deal with, and I'll force them to take it and give you an earner."
Mr Carroll was with two associates, at least one of whom would have known Mr Glen, when he was murdered. Both were not injured in the attack, the jury was told.
Mr Glen told the court it was a "coincidence" that Mr Carroll had been murdered just after their pre-arranged meeting.
However, Mr Ogg put it to him that he was an "expert liar" who was "more involved in this" than he was telling the jury.
The court heard he had not contacted police after witnessing the shooting until they tracked him down four days later.
The lawyer said: "You have lied to us. The only truth you have told is when you have known you had no other choice.
"No police officers or gangsters or even the other two people who were involved, no-one else phoned or contacted you and you don't find that curious?
"You know more about this than you are telling us."
Mr Glen said: "I told the police everything I knew, to the point I incriminated myself. I invited the police to search my house and gave them my phone. I couldn't have been more helpful."
Mr Glen said the gunmen had been shooting into the back of the Audi car from either side of the vehicle.
He said he was able to see one of them, on the drivers' side. He told the court the gunman had been wearing a green-coloured puffy jacket and a black balaclava. He agreed that he had told police in a statement that the man was between 5ft 11in and 6ft and had been shooting with a black pistol handgun.
Monaghan denies all the charges against him.
The trial before Lord Brailsford continues tomorrow.