"We believe that he's going to be our shooter. But again, I'm not gonna give his name right now. Again, we're still classifying him as a person of interest," Philadelphia Police Captain James Clark said.
It was just before 4:00 p.m. that the U.S. Marshal's Fugitive Task Force zoomed into a third floor apartment at Bartram Village in Southwest Philadelphia.
Sources tell Action News the person of interest is a 23-year-old from North Philadelphia with a long history of robbery and weapons offenses.
While his name is known, Action News is not using it because the man has not been charged with a crime.
He was supposed to report to his probation officer this morning and law officers were hoping to arrest him there, but he failed to show.
Sources say a tipster told them the suspect would be visiting Bartram Village.
He was found playing cards with another man.
The swift operation caused quite a stir among residents.
"A lot of suspects run here and give this community a bad name and we don't need that really down here," resident Alfonzo Reid said.
Investigators know the identities of the two men who are believed to be the ones seen in surveillance video released by police earlier this week.
The effort now is on catching the other one and gathering enough evidence to link them to the murder of Officer Moses Walker.
"We still have another person of interest that we want to bring in to talk to him about this particular case, so it's not over yet, it's far from over," Police Commissioner Charles Ramsey said.
Walker, a 19-year veteran had survived his shift in the 22nd Police District, only to be gunned down in civilian clothes during a robbery attempt as he walked to a bus stop near 20th Street and Cecil B. Moore Avenue.
Late Wednesday, the officer's mother joined a march organized by Mother's in Charge, a group made up of those who've lost loved ones to violence.
She broke down in tears when they arrived at the scene of the shooting & was quickly comforted by others.
Meanwhile, a police K-9 unit was unable to locate a weapon in the Bartram Village apartment.
Crews would later seal off the entry way until a forensic team can come in and sweep the place.
"We still have a lot of work to do; our homicide detectives are very good at what they do, but it's a good solid lead and we'll see where it takes us," Ramsey said.
So the intense investigation continues.
Police would like to have both men in custody and wrap this case up before the officer's viewing and funeral on Sunday.
The viewing for Officer Walker will be held on Sunday, August 26, at Deliverance Evangelistic Church, located at 2001 Lehigh Avenue in Philadelphia starting at 6:00 p.m. until 10:00 p.m.
On Monday, August 27, from 7:00 a.m. until 10:00 a.m., a public viewing will be held at the Deliverance Evangelistic Church.
Funeral services will begin at 10:00 a.m.
Committal Services will be held following the service at Fernwood Cemetery, located at 6501 Baltimore Avenue in Lansdowne, Pa.