The officers - members of the elite Viper Unit, which receives antiterrorism funds and training from the Department of Homeland Security - radioed other up the line at 5:30 p.m. to be on the lookout for the man.
Officer Felix Adorno Jr. and his partner were patrolling the bus area at the Fairmount station when the radio call came in. "We heard the trains coming in below, so we ran down" to see if it was the same train. It was.
Adorno went to search the back of the train as his partner went to the front. Meanwhile, more officers rushed over from the Cecil B. Moore station, Williams said.
The rush-hour train was packed with passengers. Adorno found the suspect hiding in the back corner of the last car. He was carrying a large black bag with a rifle sticking out, Adorno said.
Officers asked to search the bag and the man consented, Williams said.
Inside, Adorno found a .38-caliber revolver with six rounds in the chamber; the AK-47 with a 40-round clip; the 12-inch hunting knife; from 25 to 30 pills of Percocet, a powerful painkiller; more than an ounce of marijuana; and $716 in cash, she said.
The stock and the bayonet had been removed from the AK-47 so it would fit in the bag, Williams said.
Adorno described the suspect as about 5-foot-10 with a full beard and tattoos on both arms. "He had a face on him, like he was up to no good," he said.
The man kept changing his stories, Adorno said. "At first he's like, 'What guns?' " Then he claimed to have just bought them, and then said he uses them at a shooting range.
Upon closer inspection, the officers noticed that the guns were carved with the man's initials. He had no permits.
"We didn't give him a chance to react," Adorno said. "Thank God he didn't have time to grab the guns."
Passengers waited on the train for about 30 minutes while officers searched for the suspect.
Ponds was charged with weapons offenses. He was taken to the Philadelphia Police Department's Central Division, where he was held with bail set at $100,000.
Contact Jessica Parks at 215-854-2771 or jparks@philly.com.