Updated at 11 p.m. Thursday: A male student was arrested at Clarksburg High School on Thursday afternoon after allegedly bringing a loaded handgun to school, officials said.

Montgomery County police said Alwin Chen, an 18-year-old from the 11700 block of Gunners Drive in Germantown, had a 9mm handgun in his book bag and a knife in his pocket. Police are investigating his motive in bringing the weapons to school.

The arrest came a day after a former student shot and killed at least 17 people at a high school in Parkland, Florida.

Alwin Chen. Via Montgomery County police

Before 2 p.m., the school resource officer, a Montgomery County police officer assigned to the school, learned that Chen might have brought a gun to school, police wrote in press release issued at 10 p.m. Police did not say how the officer learned about the gun. The officer went with school security to Chen's classroom, told Chen they needed to speak to him and walked him to an office.

The officer then asked Chen if he had a weapon on him, and Chen replied that he had a handgun in his book bag and a knife in the front pocket of his shirt, according to police. It was about 2:20 p.m. when the officer recovered the weapons from where Chen said they were, and the officer placed him under arrest.

Chen was charged with possession of a handgun, possession of a firearm by a person under 21 and possession of a firearm on school property, according to police. He was transported to the Central Processing Unit in the Montgomery County Detention Center in Rockville.

Principal Edward Owusu wrote a letter to parents informing them of the arrest on Thursday afternoon. The letter was first reported by the Germantown Pulse.

"This illegal and dangerous behavior will not be tolerated in our school community. Weapons of any type are not permitted on or near school property," Owusu wrote. "Any student caught with a weapon will be referred to law enforcement and punished accordingly."

The handgun that police recovered. Police edited the serial number out of the picture. Via Montgomery County police

Capt. Paul Starks, a police department spokesman, said he could not confirm how the school learned that the student had a gun, but he said he did not know of any struggle while the student was arrested.

"He’s being interviewed right now, so we’re not able to confirm his motivation," he said early Thursday evening. At that time, the student had not been charged.

In a letter sent earlier Thursday to the Montgomery County Public Schools community in response to the Florida school shootings, Superintendent Jack Smith wrote about "what we do as a district to keep students safe in emergency situations," including running drills, working with law enforcement, monitoring school buildings and stressing safety measures with teachers and staff.

Police are investigating the Clarksburg High incident and collecting evidence, which will include a search of Chen's home, according to the press release. Officers are also researching the ownership and purchasing history of the handgun.

Police have asked anyone with information about the incident to call 240-773-6400.