Waltham resident Carlos Aguilar-Cruz, 24, was arraigned last Friday on the charge of armed robbery, according to a March 25 press release from Middlesex County District Attorney Marian Ryan.

Newton Police were called to a Newton middle school at approximately 2:15 p.m. last Monday to respond to a reported robbery of a 12-year-old boy.

Upon arrival, authorities were informed that at approximately 9 a.m., the student had been walking to his bus stop when Aguilar-Cruz allegedly slowed down his pace to let the student pass him and then drew a knife, tackling the boy and throwing him to the ground. Aguilar-Cruz then allegedly stole the victim’s phone before fleeing the scene. According to the press release, the student sustained minor injuries.

According to a March 25 WCVB article, the attack occurred in the area of Lexington and River Streets in the West Newton area, approximately an eight-minute drive from the Brandeis campus.

Aguilar-Cruz was arrested Thursday night after an individual spotted him walking around Waltham Common in the same clothes he had allegedly worn during the attack.

“The suspect in this case was apprehended thanks to a member of the public who had been paying close attention to the media coverage surrounding this case,” Ryan said in the press release. “This is an excellent example of the public and law enforcement sharing information to make our communities safer.”

Aguilar-Cruz was ordered to undergo a competency hearing during his Friday court appearance, according to the WCVB article.

—Abby Patkin