Wednesday's mass stabbing at a Pennsylvania high school occurred on the anniversary of one of the bloodiest school knife attacks in U.S. history — a rampage in which a Texas college student injured 14 fellow students.
There was no immediate information linking Wednesday's assault at Franklin Regional High School near Pittsburgh, with the 2013 attack at Lone Star College's Cypress-Fairbanks campus in Cypress, Texas.
In that attack, 20-year-old Dylan Quick is accused of stabbing 14 fellow students with a razor utility knife as he ran through two floors of the college's health science building. He allegedly told investigators he had been fantasizing about cutting off people's faces and wearing them as masks.
According to a search warrant affidavit, investigators seized various items from his home, including an animal dissection kit and one listed as "Hanibal Lecter Mask," a reference to the lead character in the movie "The Silence of the Lambs."
After Quick's first court appearance in May 2013, his attorney, Jules Laird, suggested that his client suffered from some sort of mental illness, but said he had not yet reviewed his health records.
Quick is scheduled to appear at a pretrial hearing on May 7 on three counts of aggravated assault with a deadly weapon and attempted capital murder, according to the Harris County District Court spokeswoman.
Grant Duwe, a criminologist with the Minnesota Department of Corrections and author of the 2007 book "Mass Murder in the United States: A History," told NBC News that he was unaware of any mass stabbings timed to mark an anniversary of a similar attack.
He also said that the use of knives is rare when attackers aim to kill multiple victims in public places.
Most knife attacks resulting in multiple deaths are "familicides," attacks involving family members, he said. There have been only seven mass stabbings in a public place in the U.S. since 1901 where four or more victims, he added, citing statistics he compiled in researching his book.