Initial reports had said that the 25-year-old had committed suicide, but police yesterday said they had shot and killed him. It turns out police only wounded him in the arm.
The incident at Dawson College in downtown Montreal left one 18-year-old woman dead and wounded 19 others. Four remain in critical condition.
Gill had posted pictures of himself on the Internet with a rifle and said he was feeling "crazy" and "postal" and was drinking whiskey hours before the attack.
The man also said on a blog that he liked to play a role-playing Internet game about the Columbine High School shootings in Colorado and wanted to die "in a hail of gunfire."
In the end, Gill — dressed in a black trench coat like the Columbine shooters — put his own gun to his head and pulled the trigger during a shootout with officers at Dawson College on Wednesday, police said.
By that time, he had already wounded 20 other people — one of whom, an 18-year-old woman, later died. Four shooting victims remained in critical condition Thursday, including three in extremely critical condition and one in a deep coma.
"Shaky. Everyone's shaky," student Marianna Rekkab, who knows some of the victims, told CBS News correspondent Randall Pinkston Thursday morning.
The Internet postings and a neighbor's description reveal an angry, solitary young man who lived with his mother, sported a mohawk, dressed in black and was filled with hatred for everyone from jocks to preppies and everything from country music to hip-hop. He once worked for a carpet company and more recently an auto parts business.
"Work sucks ... school sucks ... life sucks ... what else can I say? ... Life is a video game you've got to die sometime," he wrote in his profile for a Web site called vampirefreaks.com.
Authorities searched Gill's home Wednesday evening and seized his computer and other belongings.
"I don't know what they found in the computer," said a woman who answered the phone at Gill's home and said she was his mother. "They took everything."
She described her son as "a good man."
"Just ask anybody. Ask the neighbors. He was a good son," the woman told The Associated Press. She refused to give her name.
A neighbor across the street said he was a loner.
"There were never any friends," Louise Leykauf said. "He kept to himself. He always wore dark clothing."
Another neighbor, Mariola Trutschnigg, said she noticed a changed in his appearance in recent months when he "started wearing a mohawk and black clothes."
In postings on vampirefreaks.com, blogs in Gill's name show more than 50 photos depicting the young man in various poses holding a rifle or a knife and wearing a black trench coat and combat boots.
One photo has a tombstone bearing his name and the epitaph: "Lived fast died young. Left a mangled corpse."