Four victims of the chaotic Montreal college shooting remain in critical condition, and two are "extremely critical" with gunshot wounds to the head.

Kimveer Gill, 25, opened fire at a Montreal college on Wednesday, killing a young girl and leaving 19 wounded before police shot him in the arm. He then turned a gun on himself, an initial autopsy has confirmed.

The slain girl has been identified as 18-year-old Anastasia DeSousa, of Montreal. Her friend, James Santos, knelt by her side as Gill looked on.

"I basically stayed with her, trying to keep her awake. She was breathing, but she was not doing great," Santos told CTV News.

In a cruel twist, Santos said that Gill then turned a gun on him and ordered him to leave DeSousa behind. He then grabbed Santos.

"He told me, 'Today I'm going to die today,'" recalled Santos. "And I said, 'You don't have to, you don't have to die, you can make this easy on you and let everyone go.' ... He said, 'Well, I'm going to die.'"

Doctors are treating several victims at Montreal General Hospital, including two that are "extremely critical in the intensive care unit," according to trauma director Tarek Razek.

Two other patients are in critical condition, and one of the four is in a deep coma. But Razek said their status could change at any moment.

"It's on an hour by hour basis," he told a press conference. "We've already gone past a dozen hours, which is a good sign."

Another four victims are out of intensive care but remain in hospital.

Gill, of Laval, had a Mohawk haircut and wore head-to-toe black clothing when he stormed into the cafeteria of Dawson College, just before 1 p.m. ET Wednesday.

As horrific as the shooting was it could have easily been much worse. A police officer outside the college saw the gunman enter the building and police arrived at the scene three minutes after the man opened fire.

The 25-year-old gunman, who carried an automatic rifle and two other guns -- which were all legally registered firearms -- was shot dead as he tried to leave the school.

A blog maintained by Gill contains more than 50 photos depicting the young man in various poses holding a Baretta CX4 Storm semi-automatic rifle and wearing a long black trenchcoat and boots.

"His name is Trench. you will come to know him as the Angel of Death," he wrote on his profile on vampirefreaks.com, an online hub of goth culture.

The blog paints a dark portrait of the man.

"He is not a people person. He has met a handfull (sic) of people in his life who are decent." But he writes that he finds the vast majority to be "worthless, no good, kniving, betraying lieing (sic), deceptive."

The last of Gill's six journal entries Wednesday was posted at 10:41 a.m, just two hours before the gunman was shot dead after the college shooting.

Police had earlier believed there were as many as four gunmen.

'He shot right at us'

Panicked students described a scene of chaos and violence, as people fled or hid from the shooter.

"He shot right at us. And when he shot at us we jumped and ran the other way," said student Ali Hussein. He added that one bullet struck a wall close to where he was standing.

Another student told Montreal radio station 940 News she was on the phone at the college's front entrance when she heard five gunshots and a window breaking. She walked into the hallway and was inches from the gunman.

"All of a sudden I turned around and saw a man dressed in black with a huge assault rifle," she said. "People didn't know what was going on ... they thought it was a joke."

A number of officers surrounded the school with guns drawn, while others helped to evacuate students from inside the English-language CEGEP school which has about 10,000 students.

Police responded within three minutes

Police Chief Yvan Delorme told The Canadian Press the attacker sprayed gunfire at random targets. He said provincial police had been called in to investigate, which is standard in a killing involving the local force.

Delorme said police were able to respond quickly because two officers were already at the college on a drug-related matter when they heard gunshots and took action right away.

Delorme said the lessons learned from the 1989 Montreal Massacre when Marc Lepine murdered 14 women at Ecole Polytechnique, helped save lives. Emergency service workers now understand the need to coordinate and act quickly, and police have been trained to move in and deal with a suspected shooter right away, he said.

"Before our technique was to establish a perimeter around the place and wait for the SWAT team. Now the first police officers go right inside. The way they acted saved lives (today)."

Witnesses said Gill started shooting outside the college, then -- without saying a word-- he entered the second-floor cafeteria and opened fire. At times he hid behind vending machines before emerging to take aim -- at one point at a teenager who tried to photograph him with his cell phone.

Police dismissed suggestions that terrorism played a role, and Delorme said the gunman opened fire haphazardly at no target in particular until he saw the police and specifically took aim at them.

Police took cover behind a wall as they traded fire with the gunman, student Andrea Barone, who was in the cafeteria, told The Associated Press. He said the officers proceeded cautiously because many students were trapped around the shooter, who yelled "Get back! Get back!" every time an officer tried to move closer.

Eventually, Barone said, the gunman went down in a hail of gunfire. An initial autopsy shows that police shot Gill in the arm, and he then shot himself in the head.

Dawson College is located at the corner of Atwater and Sherbrooke in the heart of downtown Montreal.

Most of the students, who are between the ages of 16 and 18, fled to the nearby Concordia University campus where a student union barbecue was taking place. They were provided with clean clothes, beverages and even counselling.

Those services should have been provided by the Dawson College administration, said Dawson student council president Melanie Hotchkiss in a news conference Thursday with members of the Concordia Student Union.

She praised the CSU for its help but had tough criticism for her own school.

"This help was essential, and the DSU alongside the CSU were able, through solidarity, to fulfill students' needs that should have been dealt with through the Dawson administration," Hotchkiss said.

She pointed to the need for better communication and cooperation in future.

Harper says current laws don't work

Prime Minister Stephen Harper spoke only briefly to the media Thursday afternoon, saying it was not appropriate to comment without knowing all of the facts.

"We can obviously just observe that laws we have didn't prevent this tragedy, which is why our government in the future, because of this incident and many others, are looking to make our laws more effective," he said.

Harper said debates are sure to unfold about the government's role of censorship in video games and the monitoring of the Internet.

"We as a society have trouble squaring our outrage at some of the images that we see, some of the images that are communicated to people, young people in particular. We have trouble squaring that in our belief of freedom and our desire to avoid censorship," he said.

"However terrible images or messages that are sent to people or people may see ... they do not absolve any of us from our moral responsibilities as individuals to act in ways that treat our fellow human beings with decency."

Harper offered condolences to the family of the young woman killed in the rampage and said his thoughts are with the victims still in hospital and the people horrified by the ordeal.

He said he spoke to Quebec Premier Jean Charest and Montreal Mayor Gerald Tremblay Wednesday night and offered any help they might need from the federal government.

With a report by CTV's Genevieve Beauchemin in Montreal