Gordon, 26, was denied bail and remanded to the Bucks County Correctional Facility, said the District Attorney's Office.
6abc reports that prosecutors will seek the death penalty in Gordon's case.
Authorities have said he killed his 52-year-old stepmother Karen Gordon, his 13-year-old sister Kera Gordon, and 25-year-old Taylor Daniel, with whom he had two children, on March 16.
Investigators said the deadly spree began just before 9 a.m. when he arrived at his father and stepmother's 45 Viewpoint Lane home in Falls Township. He smashed the window and fired a rifle into the home, fatally shooting Karen and Kera Gordon, authorities believe.
Less than 10 minutes later, Gordon shot and killed Daniel at her Edgewood Lane home in Levittown, according to officials.
Police said he beat Daniel's mother with the butt of his rifle before fleeing the scene, stealing a car at gunpoint, and heading to Trenton.
He was arrested there hours later, authorities said.
Gordon is charged with three counts of murder and related offenses, the DA's Office said Wednesday.
Click here to follow Daily Voice Allentown and receive free news updates.