In September last year the dealer met with an associate of Bourne, nicknamed "Mad Bitch" in messages, who gave him the ice to sell.
Comanchero Alex Bourne smashed drug dealer's hand with sledgehammer
He and the woman met another man with the intention of selling the ice, worth about $5300 on the street, but during the meeting the other man stole it, the documents suggest.
Bourne, 30, "wasn't very happy" about the theft, and soon contacted the dealer over Facebook, saying he had an hour to meet him in Gungahlin.
It was about midnight, and when the dealer arrived Bourne led him to an underground car park and demanded he hand over rings, a watch, and $2000 in cash.
Bourne, who admitted the crimes in court on Monday, then picked up a sledgehammer and told the dealer to put his hand on the concrete.
He complied, believing Bourne wanted to scare him, but the Comanchero hit the dealer's hand multiple times with the sledgehammer.
One strike caused the bone on top of the man's hand to protrude and the man was in "extreme agony", the documents say.
Bourne kept hitting the man's hand and he "struggled to breath and his leg started to twitch".
He later had surgery at hospital but doctors may still have to amputate a finger that has limited movement, the documents suggest.
The man's mother became involved and started paying off the debt purportedly owed by her son to Bourne.
In one incident, the drug dealer led police on a pursuit because he had in his car drugs to be sold to settle his debt with Bourne.
Once he disposed of the drugs he made full admissions to police about the police pursuit.
Police said that showed the fear he had of Bourne and of losing the drugs a second time.
Blackmail and trafficking
In December last year Bourne learned a different man had been selling a small amount of MDMA, tendered police allegations say.
Bourne knocked on the man's door and introduced himself as "Alex" and a member of the Comanchero. He accused the man of putting a "dint" in their wallets and said it was unacceptable the man would sell drugs in competition with the gang.
He said instead of tying the man up, putting a gun in his mouth and shooting him they had come to talk about an arrangement.
The man refused to work for the Comanchero selling drugs, but said he would pay Bourne, to compensate the gang for its loss and punish him for selling in their "territory".
He gave $1100 to Bourne, who said that wasn't enough, but he agreed to leave.
A few hours later Bourne sent the man a message on Wickr. Bourne's username on the encrypted messaging app was "Elchapo2615".
The message said "we have been more than reasonable, my bosses have told me to get $10k off you. What are you going to do about it?"
He agreed to give Bourne $6000, his entire savings, if they left him alone after that.
But after handing over the money he received a text from someone else demanding $15,000.
He feared no matter what he handed over the group would continue to threaten him.
In what was a controlled police operation, Bourne met the dealer at a garage last December to give him drugs to sell.
Police say Bourne trafficked MDMA when he handed 28 grams of the drug to the dealer.
At an arraignment in the ACT Supreme Court on Monday, Bourne, of Gungahlin, admitted to a count of intentionally inflicting grievous bodily harm, one of blackmail and one of trafficking in MDMA.
He remains in custody.
He returns to court on February 20 for sentence.