The 23-year veteran of the force lost his life early Sunday morning after he finished his shift, hit by an alleged drunk driver going the wrong way on I-95.
At Friday's service, a mournful wail of bagpipes could be heard as pallbearers carried the casket from a horse-drawn hearse.
The echo of thousands of footsteps were heard as police officers from around the country filed by to salute a fallen comrade.
Along with that, the tears of a brother, also a police officer, as he struggled to find the right words.
"I miss Brian so much already. I struggle with his death everyday and often wonder how such an honorable man could be taken from us so suddenly," said Manny Lorenzo, brother.
The funeral service played out inside a packed cathedral while outside, an overflow crowd watched on a giant television screen.
"We're all one police department no matter where you work - Philadelphia, Baltimore, New York. If something happens to one of our brothers we have to come support him," said Sgt. Lennardo Bailey of Baltimore, Maryland.
Officer Lorenzo was a co-captain and instructor for the elite Highway Patrol motorcycle drill team. His former colleagues came from as far away as Florida.
"We were on highway patrol together. I was an instructer on the motorcycle drill team and Brian made the team. Once you're on the drill team and on highway patrol, you're like family. We had to come up here," said Sherriff Frank Flynn of Lee County, Florida.
Lorenzo leaves behind his wife Linda and three children. A touching moment - as the casket was loaded into the hearse - 4-year-old Domenic Lorenzo tried to cheer his mom with a kiss.
Hundreds of motorcycles escorted the hearse as it departed for the cemetery with badge number 5591 on the back window.
It's a scene that Mayor Michael Nutter says has played out far too often.
"Much of this could be prevented if people would just do what they're supposed to do and not be irresponsible. Ultimately its always about personal behavior and personal decisions that people make,: said Mayor Nutter.
It was a sad goodbye to a man who loved his job and his family but also a grateful city's thanks for a job well done.
Meanwhile the man behind the wheel during the crash - John Leck Jr. of Levittown is charged with third-degree murder, vehicular homicide while DUI, involuntary manslaughter and other offenses.
Information provided by The Associated Press was used in this report.