Donnell Murchison pleaded guilty on Monday to two counts of first-degree murder and was sentenced to life in prison.
Langdon Scott pleaded guilty to robbery, burglary and conspiracy charges.
Those pleas came as jury selection was set for those two men along with four other defendants in the killing of 34-year-old Rian Thal and 40-year-old Timothy Gilmore.
They were killed in June, 2009 inside the Piazza at Schmidts apartment building in Northern Liberties in what investigators called a botched drug-related robbery.
Investigators seized four kilograms of cocaine and more than $100,000 from Thal's apartment following the shooting.