TORONTO — A man who witnesses said stabbed and beheaded his seat mate on a Greyhound bus in Canada made his first court appearance today, while police offered no motive for the savage attack against a 22-year-old carnival worker.

Vince Weiguang Li, 40, of Edmonton, Alberta, has been charged with second-degree murder. He shuffled into the courtroom in Portage la Prairie, Manitoba with his head bowed and feet shackled.

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 Royal Canadian Mounted Police said Li has no known criminal record.

Authorities have not released the victim’s name but friends identified him as Tim McLean and said he was headed to Winnipeg after working with the carnival in Edmonton.

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.

Friends started a Facebook group called “R.I.P. Tim” after news of the attack.

“He was a great person, he was kind, thoughtful, and he did not deserve this. I feel for his parents and sisters and his lil bro,” Jossiee Kehleer wrote on the site.

Passengers said the victim was stabbed dozens of times Wednesday night aboard the bus as it traveled a desolate stretch of the TransCanada Highway about 12 miles from Portage La Prairie.

Witnesses described a grisly killing that occurred as some passenger were napping and others watching “The Legend of Zorro” on television screens inside the bus. Greyhound spokeswoman Abby Wambaugh said there were 37 passengers on the bus at the time.

Shortly after passengers reboarded following a break, the suspect — for no apparent reason — stabbed the man sitting next to him several dozen times as others fled in horror, witnesses said. He then severed the man’s head, displayed it and began hacking at the body.

Garnet Caton, who was sitting just one seat in front of them, said the suspect had been on the bus about an hour. He initially did not sit near the victim but changed seats after a rest stop. Caton said he did not hear the two speak to each other before the attack.

“We heard this bloodcurdling scream and turned around, and the guy was standing up, stabbing this guy repeatedly,” Caton said.

Caton watched in horror as blood sprayed across the back of the bus, he told The Globe &Mail daily.

“He had a Rambo, hunting knife covered in blood and he just kept going at the guy,” Caton said. “He was very calmly killing the guy and the other guy was screaming bloody murder,” he added.

“There was no rage or anything. He was just like a robot stabbing the guy,” Caton said.

Caton said the driver stopped the bus when he became aware of the attack and passengers raced off. A short while later, Caton said he re-boarded along with the bus driver and a trucker who had stopped to see what was happening.

He said the suspect had the victim on the floor of the bus and “was cutting his head off” with a large hunting knife.

The attacker turned toward them and the three men quickly left the bus, blocking the door as the attacker slashed at them through an opening. Caton said the driver disabled the vehicle after the attacker tried to drive it away.

As the three guarded the door with a crow bar and a hammer, the attacker went back to the body and calmly came to the front of the bus to show off the head, Caton said.

Public Safety Minister Stockwell Day called the attack bizarre and extremely rare.

“The horrific nature of it is probably one-of-a-kind in Canadian history,” Day said.