The escape happened around 8:30 p.m. when the individuals were seen on surveillance footage cutting a hole in a fence at the Philadelphia Industrial Correctional Center (P.I.C.C).
Police told ABC Philadelphia affiliate WPVI that one of the inmates, Ameen Hurst, 18, was being held on several murder charges.
Deputy Commissioner of Investigations Frank Vanore said one homicide took place on Christmas Eve in 2020.
Police searching for 2 inmates who escaped correctional center
Vanore stated that in March 2021, Hurst committed three more murders. He said Hurst shot four people and killed two behind an apartment building on March 11, 2021.
Then, just days later on March 18, officials said Hurst shot and killed Rodney Hargrove roughly one hour after he was released from the Curran Fromhold Correctional Facility.
READ | 16-year-old connected to 4 Philly murders, including shooting near prison
The second inmate who broke out of the Philadelphia Industrial Correctional Center is 24-year-old Nasir Grant, who police said was being held on narcotics and gun violations.
Officers said the only connection between the two inmates is that they were housed in the same unit but in different cells.
How prison break went undetected for hours
According to Prisons Commissioner Blanche Carney, the Philadelphia Industrial Correctional Center became aware of the two escaped inmates about 3 p.m. Monday.
Carney said there were three headcounts which took place at 11 p.m. Sunday, 3 a.m. Monday, and 7 a.m. Monday before learning of the escape.
It's still unclear how the missing inmates went under the radar.
"So the facility became aware today at their 3 p.m. headcount that we had two individuals that were not accounted for. They're going back through the process to see if those three counts that were called in as cleared and why they did not detect those two individuals missing," said Carney.
WPVI asked Carney if she believed someone on her staff aided in the escape or if it was a case of negligence.
She responded by saying we would have to wait for an official investigation.
Mayor Jim Kenney said at a news conference Monday evening that they want to find out exactly what happened.
"Clearly the system screwed up and people didn't do what they're supposed to do," Kenney said.
In the meantime, police officials ask the public to be cautious of these individuals.
Officials said if you see either of the inmates or know of their whereabouts, call the police tip line at 215-546-TIPS or call 911 immediately.