A Boston teen is being held without bail after being charged with stabbing a 63-year-old man outside a luxury Beacon Hill hotel in front of multiple people.

“This is yet another example of on-the-spot witness information helping lead to quick identification and arrest,” Suffolk District Attorney Kevin Hayden said in a press statement. “The number of people at the scene and the severity of the victim’s injuries adds to the shocking nature of this incident.”

Kymani Walker, 19, of Boston was charged earlier this week in Boston Municipal Court with assault and battery with a dangerous weapon — a knife — and armed assault to murder. Judge Paul Treseler ordered Walker held without bail ahead of a competency hearing scheduled for Aug. 16.

Police responded to the Liberty Hotel at 215 Charles St. at around 4 p.m. Saturday. Witnesses there told police that they heard the victim shout “I don’t know you” as Walker — in “a fighting stance,” per a DA statement — lunged at him several times with a knife before ultimately stabbing the victim in the stomach. The victim was found lying on the sidewalk suffering from multiple stab wounds and was transported to an area hospital.