Protesters gathered Sunday night outside the Lehigh County Prison in Allentown.
They were calling for the Lehigh County District Attorney to reopen the death investigation of an inmate.
Alphie Herrera Senior died in February of last year.
At the time., DA Jim Martin said Herrera suffered a seizure in his cell and became violent when medical staff tried to help him.
He said after being placed in a restraint chair, Herrera's condition began to deteriorate and he was taken to the hospital.
He later died at the hospital.
No charges were filed in the case.
The protesters said they are fighting to bring justice in Herrera's death.