A Canadian man was charged with first-degree murder Friday for fatally shooting his father in the back with a crossbow in a Toronto library as shocked mothers and children watched.

Zhou Fang, 24, appeared in court to face the murder charge a day after Si Cheng, 52, was killed in the library about an hour after a nearby school let out for the day. The judge ordered that Fang be held without bail.

Toronto police Const. Tony Vella said Cheng was pronounced dead at the scene and Fang was arrested later Thursday in a Toronto suburb.

"The use of a crossbow is definitely a unique case in Toronto," said Vella. "You hear about guns, you hear about knives being used, but you definitely don't hear about a crossbow."

Earlier Friday police said the two men knew each other, and Vella later confirmed the men were father and son. Police did not say what caused the altercation.

Toronto Public Library spokeswoman Anne Marie Aikins said the popular neighborhood library was busy with its after-school and mother-and-children programs at the time. Babies were among those in the branch when Cheng was killed, she said.

Although there were many witnesses, police have not yet confirmed if anyone noticed the weapon before the attack.

The library remained closed Friday for the police investigation.

Residents near the library were stunned by the unusual attack.

"This street is full of kids ... It's very traumatizing," said Linus Smith, who was sitting in a restaurant across the street when she said the suspect came out of the library with something in his hand, got into a U-Haul truck and drove off.

"It's shocking," said Troy Ross, 39, who lives across the street from the library and often takes his children there. "You don't think of a crossbow as something for killing people, just as something for recreation."

The Royal Canadian Mounted Police reports the only crossbows prohibited in Canada are those that can be fired with one hand and are 19 inches (50 centimeters) or less in length. A license or registration certificate is not required to own crossbows longer than 19 inches that require two hands to use. Such crossbows are sold in hunting shops across Canada.

Vella would not reveal what type of crossbow was used in Thursday's killing but said the suspect has not been charted with any weapons violations.

This is not the first incident involving crossbows in Canada.

In 1991, a woman was shot dead by her estranged husband with a crossbow on an Ottawa, Ontario, street. A father was charged in July with wounding his 36-year-old son with a crossbow in British Columbia.