On the tape, which lasts about 80 seconds, officers continue to detail the attacker's movements until one reports, "Badger's at the back of the bus, hacking off pieces and eating it."
The RCMP described the tapes as "operational police communications and, as such, are not meant for public consumption." Police said permission had not been given to use the radio transmission, which was posted on LiveLeak.com and picked up by other Web sites.
Officers were responding to a desolate stretch of the TransCanada Highway about 12 miles from Portage La Prairie, Manitoba, after the bloody attack late Wednesday on the bus traveling from Edmonton, Alberta to Winnipeg, Manitoba.
Vince Weiguang Li, 40, faces second-degree murder charges for the murder of a 22-year-old man, who friends and family identified as Tim McLean. Police have not confirmed the victim's identity.
Passengers said they had just reboarded the bus following a break when the suspect - for no apparent reason - stabbed the man sitting next to him dozens of times as passengers fled in horror.
He then severed the man's head, displayed it and began hacking at the body.
Li's employer said in an interview Saturday that he was shocked to learn that his "model employee" had been accused of the grisly attack. Vincent Augert, an independent contractor who distributes newspapers in Edmonton, said that Li was one of his most reliable carriers.
"He was very punctual and always cleanly dressed," he told The Associated Press. "He was a very nice, polite guy. We would've had no reason to let him go before all this happened."
Augert said Li had worked for him since last July and caused no problems.
"I had no odd suspicions about him at all," said Augert.
Augert said that Li called him two weeks ago to say he needed a day or two off to go to Winnipeg for a job interview at the end of July. He said Li called him back and left a message with the dates, but never followed up after that.
"That was unusual for him not to call back and then when he didn't show up for work on Tuesday we got worried," said Augert, who said it was sometimes difficult to understand Li because he spoke quickly and had a strong Chinese accent.
Augert said he called Li's cell phone on Thursday and his wife answered. She told him that she hadn't heard from Li, who had told her he had to leave for a few days because of a family emergency.
Li, who shuffled into a courtroom Friday in Portage la Prairie with his head bowed and feet shackled, appeared before the court without a lawyer. He did not reply when the judge asked him whether he was going to get a lawyer, and only nodded slightly when asked whether he was exercising his right not to speak. He was not required to enter a plea.
The prosecutor asked for a psychiatric assessment, but the judge said he wanted to give Li a chance to meet with his lawyer. Li's next court appearance is scheduled for Tuesday. The RCMP said Li has no known criminal record.
McLean's family spoke publicly Saturday for the first time since the brutal attack.
"He was a little guy with a heart bigger than you could know," McLean's uncle, Alex McLean, told reporters in a prepared statement from the family.
"Tim spent his life traveling and meeting new people and always saw the good in everyone. He had the most infectious giggle. You could hear him laughing a mile away," said Alex McLean.
"It didn't matter what kind of a day you were having, because when you heard him laugh, you couldn't help but join in."
William Caron, 23, said McLean was quiet, though he liked to socialize with friends. He was small - about 5-foot-4 and 130 pounds - and tended to stay away from a fight, Caron said.
"All the time I've known Tim, he's never been the type of guy to get into a fight with. He always kept to himself when there's strangers around," Caron said.
The killing has spawned a vast online community, with tens of thousands showing support for McLean's family and expressing disgust for the attack.
One of the many groups on the social networking site Facebook has accumulated over 40,000 members with more than 2,000 wall posts.
"It's something right out of a horror movie," said Sheena in Edmonton.