EMBED >More News Videos A 20-year-old man was arrested after causing quite a scare with a drone that police say he was operating over protesters in Center City.

UNIVERSITY CITY (WPVI) -- A 20-year-old Drexel University student was arrested after police say he was operating a drone over a protest in Center City Philadelphia.Joseph Roselli has been charged with aggravated assault, causing/risking catastrophe, simple assault and recklessly endangering another person.Action News was there as Roselli reunited with his parents Thursday after being arraigned in court.As a group of about 300 protesters marched through the streets Wednesday night, its alleged Roselli piloted his small drone from the rooftop of his apartment building near at 30th and Chestnut.It's alleged the drone nearly hit a police helicopter says Chief Inspector Joseph Sullivan."The drone came directly at the front of the helicopter. The pilot was initially unsure whether it actually hit the windscreen or the windshield of the helicopter before it veered off," said Philadelphia Police Chief Inspector Joe Sullivan. "At another time, it approached the helicopter from the side and got extremely close, and, at the last minute, dove and went under the helicopter."Roselli was taken into custody Wednesday night. Police say his drone flew for several miles at an altitude of up to 1,500 feet, and was operating at times in restricted airspace."He is in restricted airspace due to heliports a Hahnemann University Hospital and Thomas Jefferson University Hospital," said Sullivan.So how could a 5-pound drone be a threat to a 3,000-pound helicopter? The concern is it could be sucked into the air intake of a turbine engine or damage its rear rotor, which is used for directional control."If it had struck the rear rotor, we could have had an aircraft that was completely out of control dropping into Center City," said Sullivan.Joseph Roselli declined to talk as he left Central detectives.His parents describe him as a bright kid who made a bad decision, and he must now face the consequences."He's just a geeky kid, 20-year-old kid, and he was just playing with his toy, and unfortunately it ended up in the wrong place, and that's basically it," said Frank Roselli, father. "He didn't have any intentions of hurting anybody."