The teenager accused of carrying out a deadly attack at a Toronto massage parlor was reportedly inspired by the "incel movement"—a subculture known for its misogynistic and violent ideology.

According to Global News, Toronto authorities confirmed they were treating the case as an act of terrorism, marking the first time the country has added terrorism charges to a suspected incel-related crime. Incels, short for "involuntary celibates," is male-dominated online community that often promotes attacks against women as a form of retribution for sexual rejection.

"What begins as a personal grievance due to perceived rejection by women may morph into allegiance to, and attempts to further, an incel rebellion," a Texas Department of Public Safety report states about the incel movement. "The result has thrust the incel movement into the realm of domestic terrorism."

The deadly attack occurred on Feb. 24 at Crown Spa, an erotic massage parlor that advertised a "sensual body rub" and "an exotic massage that will leave you feeling completely relaxed and spoiled senseless." At around 12:40 p.m., police responded to a report about a stabbing rampage at the establishment. Shortly after they arrived, police found 24-year-old mother Ashley Noell Arzaga dead inside the establishment. Authorities also found a man and woman with non-fatal stab wounds outside the parlor.

The owner told investigators she heard screams from a back room and went to see what was going on. Once she entered, the suspect allegedly stabbed her with a machete; however, she managed to wrestle the weapon away from the teen and stab him in the back. Authorities arrested the alleged murderer at the scene, before transporting him to the hospital.

Though the motive behind the attack has not been disclosed, sources told the outlet the 17-year-old suspect, whose identity is protected under the Youth Criminal Justice Act, was familiar with Elliot Rodger, the 22-year-old man who became an "incel hero" after murdering six people in 2014. 

During a court appearance Tuesday, the teen was informed his first-degree murder and attempted murder charges were upgraded to first-degree murder - terrorist activity and attempted murder - terrorist activity. He faces an automatic life sentence if convicted.