The 18-year-old freshman who stabbed four people on the University of California Merced campus Wednesday was shot dead after he lunged at a police officer with his hunting knife, a fellow student said.

Meghan Christopherson, a 19-year-old sophomore, tells the Fresno Bee that an officer was chasing 18-year-old Faisal Mohammad when he suddenly stopped to face the officer.

She says Mohammad began walking toward the officer. The officer backed up, repeatedly telling Mohammad to get on the ground. She says the officer kept asking Mohammad if he wanted to get shot.

When Mohammad lunged, a frightened Christopherson ran away. She heard two shots and turned to see the officer standing over Mohammad's body.

She says it all took less than a couple of minutes.

More On This...

Mohammad burst into a classroom with the knife after being kicked out of a study group, investigators say. A coroner performing an autopsy on Mohammad found the suspect's manifesto on his body, according to Merced County Sheriff Vern Warnke.

Mohammad listed the intended targets by name in the manifesto, and planned to tie students to desks while drawing out police to steal a gun and shoot people, Warnke said. The blade of his hunting knife was 8 to 10 inches long, according to authorities.

The freshman also planned on using the petroleum jelly found in his backpack to squirt on the floor as a slip-and-slide for anyone entering his classroom, which according to Warnke, he thought would allow him to be in a position to steal a gun from a responding police officer.

“His plan went haywire because people fought back,” Warnke said Thursday night. “He got so befuddled at the activities that happened; it took the script away from him.”

Warnke stressed Wednesday’s stabbings were not terrorism, just a grudge by an angry teenager, but Mohammad did praise Allah in his writings. He added though that the writings about Allah would be like him, a Christian, referencing Jesus, since that is the religion he practices.

Mohammad, who was killed by campus police, was described by at least one witness as smiling as he slashed at victims, called a loner by a fellow dorm resident and drew praise Thursday from a Twitter account associated with ISIS, which just last week released a series of videos calling for lone wolf stabbing attacks.

“May Allah accept him,” read a tweet in Arabic from a Twitter account that terrorism experts say has carried previous ISIS propaganda, just minutes after Mohammad’s name was divulged by campus authorities.

"He had a smile on his face, he was having fun," a construction worker who helped stop the attacker told CBS 47.

A suitemate said Mohammad "didn't talk much." Speaking to KFSN, Andrew Velasquez said he never saw the stabber walking to class with anyone, adding, "Every time I would try and say something he would just ignore it."

The four victims are expected to survive.

Classes resumed Friday. Chancellor Dorothy Leland welcomed back students with a message to "practice kindness" and offer support to one another.

The classroom where the stabbings took place and an adjacent classroom still are closed as part of the investigation.

The Associated Press contributed to this report.