LOWER MANHATTAN, New York City (WABC) -- Convicted cop killer Herman Bell's pending parole is drawing outrage from Patrolmen's Benevolent Association (PBA), the family of one the officers killed 47 years ago, and even the mayor."I'm very troubled by it," Mayor Bill de Blasio said. "This was a premeditated killing of the police officer. That should be life in prison, period."Surrounded by a blue wall of NYPD officers, the wife of one of the officers killed and her two daughters, Deborah and Mary, condemned parole board members who are releasing Bell."They were assassinated only because they wore the blue uniform," said Diane Piagentini, widow of slain NYPD Officer Joseph Piagentini. "No other reason."Answering what turned out to be a bogus 911 call in May 1971, Officer Piagentini and his partner, Officer Waverly Jones, were ambushed by Bell and two other members of the Black Liberation Army, a militant group."This animal took his weapon and pumped 22 rounds into him," PBA President Pat Lynch said. "One. Two. Three. Four. If you ever shot a gun, you know how difficult that is."Herman Bell and the two others were convicted and sentenced to 25 years to life, the most serious penalty at the time. Now, police and the victim's families are demanding the two parole board members be fired."The parole board has chosen to release one of the most dangerous criminals of our time," Diane Piagentini said. "Commissioner Otis Cruze and Commissioner Carol Shapiro, they should be fired."Bell's supporters, including relatives of one of the slain officers, said the 70-year-old was a model inmate who deserved freedom. The union disagreed."They've lost the vision of what's right and what's wrong," Lynch said. "This decision is wrong."Bell had been denied parole seven times before. But in a decision released Wednesday, a parole board said Bell's "debt has been paid to society" after he admitted his crime, was productive in prison and amassed supporters.----------