ABC News January 4, 2015

Funeral Held for Second Slain NYPD Officer

WATCH: Police Officers Again Turn Backs on De Blasio

Thousands of mourners gathered today at a funeral home in New York City to remember Wenjian Liu, one of two city police officers killed in a shooting last month.

Undaunted by chilly rain, a steady stream of men and women in blue marched past the funeral home to pay their respects to Liu's weeping family, , and later saluted as pallbearers carried Liu's coffin, draped in the NYPD flag, to a waiting hearse.

NYPD
New York Police Department officer, Wenjian Liu was killed Dec. 20, 2014, as he sat in his car in the Bedford-Stuyvesant neighborhood of Brooklyn.
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Following a private Chinese ceremony led by Buddhist monks at Aievoli Funeral Home, dignitaries and family members today memorialized Liu, 32, in a traditional police ceremony.

"These are our most difficult days. They are days where we struggle to define meaning from tragedy," FBI Director James Comey said. "Our obligation is to make something good come from tragedy so that evil is not allowed to hold the field, so that evil is not allowed to win the day. Our obligation is to try to do good to honor this man."

Mayor Bill De Blasio delivers remarks at the funeral for New York City police officer Wenjian Liu on Sunday, Jan. 4, 2015.

Before Liu's wake, NYC Police Commissioner Bill Bratton sent a warning to officers who planned to attend the funeral, saying the ceremony should be "about grieving, not grievance." Protests "stole the valor, honor, and attention that rightfully belonged to the memory of Detective Rafael Ramos's life and sacrifice," he wrote in a letter sent to officers.

As officers outside protested his speech, the mayor recalled the way Liu "transformed" everyday tasks in to moments "of profound humanity and kindness."

After Liu and a partner had responded to a call from an elderly resident who had fallen down, "Detective Liu was not ready to leave. The man he came to help was an army veteran who served in Vietnam, and he was lonely and he wanted to talk about his life," de Blasio explained. "Detective Liu sensed this. So he poured the man a soda and listened...

"New York City stands a little taller today because he walked among us," he continued. "With hearts that are doubly heavy from the loss of Detective Liu and Detective Ramos, let us rededicate ourselves to those great New York traditions of mutual understanding and living in harmony. Let us move forward by strengthening the bonds that unite us. And let us work together to obtain peace."

Liu "took pride in the fact that he is NYPD," his wife, Pei Xia Chen, said through tears. "We spoke about work often, how much respect he had for the law, how he applied the law. He was objective in his determination of the law, with courtesy, respect, and with the highest professionalism."

"Although he worked often, he would always make sure to take time for me, his number one fan, his family and his friends," she said. "Wenjian is my hero."

In the two weeks since the Liu and Ramos' death, at least 18 people have been arrested for threatening police, according to the NYPD.