The slain Good Samaritan, Jamie Kehoe, 18, was on a bus in Newton about midnight Friday when he allegedly was stabbed in the neck by a fellow passenger while interceding with the fighting women, The Vancouver Sun reported.
"He was grabbing her, [one of the women] and gasping, and when he fell, he fell on her she started screaming for someone to call the cops, call 911," his mother Tammy said.
The alleged assailant, described as a black male about 6 feet tall, fled the bus with one of the women involved in the altercation.
Despite following a blood trail 3 blocks long, police had not arrested anyone, the Sun reported.
The Royal Canadian Mounted Police is investigating.
Tammy Kehoe is urging anyone with information to contact authorities.
"Somebody had to have seen something, someone must know him [the suspect]," she said. "Somebody has to know something, somebody has to help find him -- he's running around free."