While police from Jenkintown and Abington and Cheltenham townships searched for Borden, the Jenkintown School District was placed in a Level 2 lockdown from 10 a.m. to 11 a.m.
A pair of officers stopped him near Rodman Ave. and Old York Road in Abington and questioned him. Borden, of Warminster, provided a false name. Then he broke away and ran. Police pursued him through a yard, down an embankment and onto the commuter tracks.
Borden was running along the rails towards Philadelphia while officers trailed him. As the West Trenton Local approached, police watched as Borden jumped in front of the train, DiValentino said.
Police tried to revive him until emergency crews arrived. Borden was taken to Abington Memorial Hospital where he was pronounced dead.
Service on the West Trenton Regional Rail Line was suspended for about 15 minutes, a SEPTA spokesperson said.
Jenkintown School District Superintendent Timothy Wade said police did not provide details of the police activity when they requested the lockdown.
"This is standard procedure. We practice this with police," Wade said. "When they call, we don't ask questions. Later, probably, this afternoon, we'll evaluate how we did."
During the lockdown, the 600 students were locked in their classrooms, with limited movement within each of the schools.
"The teachers knew exactly what to do," Wade said. "There was no worrying or upsetting the younger children."
Contact Bill Reed at 215-801-2964, firstname.lastname@example.org, or follow @BReedBucks on Twitter. Sam Wood contributed to this article.