Members of the Philadelphia chapter of Al Sharpton's group, the National Action Network, were joined by others in criticizing the FOP for throwing what the group called "a bash" for the officers.
Back in 2008, 8 Philadelphia police officers drew international attention when a news helicopter captured video of them kicking and beating three murder suspects.
Commissioner Charles Ramsey fired, demoted, and suspended the officers involved. But a grand jury cleared the officers of any wrongdoing and a separate jury acquitted the three suspects.
Just last week, an arbitrator ruled the officers should get their jobs back with back pay.
As a result, the FOP decided to have a welcome back affair with free beer and food.
"We'll stand behind our officers because that's what we do and we do it very well," FOP president John McNesby said.
Relatives of the three men who were beaten were outraged over the affair.
"For them to hold a party is a slap in the city's face and the mayor should be out here with us protesting," Jackie Gibbs, one of the men's aunt, said.
"I believe I am owed an apology, my son is owed an apology. They got their jobs back, they're over there celebrating. For what?" Michelle Wood, a mother of one of the men, said.
Meanwhile, McNesby called some of the protestors, which included MOVE figure Pam Africa, professionals, who stage protests in front of FOP every other week.
"These guys were vindicated. Where were they protesting for the families in support of police during times when we had officers getting killed in the line of duty?" McNesby said.
The National Action Network says Al Sharpton himself will be in Philadelphia next week.
