Mourners Gather for Funeral of Slain NYPD Det. Wenjian Liu View Full Caption

DYKER HEIGHTS — Hundreds of NYPD officers turned their backs on Mayor Bill de Blasio as he spoke at murdered Det. Wenjian Liu's funeral in Brooklyn Sunday, defying pleas from Commissioner Bill Bratton not to protest as the city and department mourned.

Liu was assassinated along with his partner, Det. Rafael Ramos, in Brooklyn last month. A seven-year veteran, he was married just months ago and was looking forward to starting a family, his devastated widow, Pei Xia Chen, said after the Dec. 20 shooting.

"You are an amazing man," a tearful Chen told mourners of her husband. "Even though he left us early, I believe that he is there with us. His spirit will continue to look after us."

Pei Xia Chen was presented with a flag after the funeral for her husband, Det. Wenjian Liu. View Full Caption DNAinfo/Ben Fractenberg

When de Blasio addressed the mourners at Aievoli Funeral Home, throngs of officers from the NYPD and several other departments, lined up on 65th Street, between 14th and 15th avenues, turned their backs on the mayor, despite Bratton's warning a day earlier at Liu's wake that "a hero’s funeral is about grieving, not grievance."

Most of the officers directly in front of the funeral home, near 13th Avenue, remained facing forward and at attention.

More than a dozen declined comment when asked by a reporter why they turned their backs on the mayor.

But one officer from Concord, Calif., who declined to give his name, said that he turned his back "to back our brothers from the NYPD."

The NYPD did not immediately comment and the mayor's office did not directly address the issue in a comment.

"Today we honor the legacies of Detectives Liu and Ramos, and remember their dedication to serving the people of New York City," said spokesman Phil Walzak. "Our city and this Administration are focused on doing everything possible to support the grieving families of our fallen heroes."

The act of defiance came just days after hundreds of officers turned their backs on the mayor at Ramos' funeral in Queens and comes amid a deepening rift between the department and city hall.

Union officials held the mayor responsible for the officers' deaths after remarks he made following the apparent police chokehold death of Eric Garner, including warning his son, Dante, who is mixed race, about the dangers he faced in interacting with police officers.

Thousands of law enforcement officers from around the country, including FBI Director James Comey, attended the emotional service and many stood outside in the rain to honor Liu.

Deputy Sheriff Tony Gower, of the Iron County Sheriffs' office in Utah, said that the deaths of Liu and Ramos were "gut-wrenching."

"We came out to show our support," he said.

Also attending the service with de Blasio was his wife, Chirlane McCray, Bratton and politicians such as Reps. Grace Meng and Peter King.

"All of city is heartbroken today," de Blasio told mourners. "Det. Wenjian Liu was a good man. He walked a path of courage, a path of sacrifice, a path of kindness...and he was taken from us too soon."

A solemn de Blasio recounted Liu's path to the NYPD and his devotion to the department and his family.

"Det. Liu lifted all of us up," he said. "New York City stands a little taller today because he walked among us."

Liu and Ramos, who were assigned to the 84th Precinct, but were working a special detail to reduce crime in housing projects, were sitting in their patrol car on Tompkins and Myrtle avenues when gunman Ismaaiyl Brinsley walked up and opened fire.

Brinsley then fled into a nearby subway station and killed himself.

The murders came amid a series of anti police-brutality protests sparked by the deaths of Garner and Mike Brown in Ferguson, Mo. and Bratton said they were a "direct spinoff" of that movement.

"Let us work together to attain peace," de Blasio said before he left the stage to silence.

Liu, who friends and colleagues knew as "Joe," came to the United States in 1994 and joined the NYPD in 2007, using his language skills in his work for the department. He was planning to be an accountant, Bratton said, but 9/11 changed his path.

"Why do we always lose the good ones," asked Bratton, who choked up during his remarks.

Liu, who was promoted posthumously to first-grade detective, was mourned as a man who was devoted to his family, the Chinese community and the department. There was a traditional NYPD ceremony as well as a Buddhist ceremony.

"He loved his family and they certainly loved him," Bratton said. "At the end of every tour he would call his father to let him know he was safe."

Bratton said that Liu was "a good man, a humane man. He was a New York City cop."

De Blasio recalled that Liu loved fishing and shared his catch with his family. He also loved to cook for his mother and father.

One of his proudest moments was buying his parents a house and paying for their mortgage, the mayor said.

Liu's father, who spoke in Chinese, was overcome with emotion during his remarks.

"Wenjian, you are the best son," he said, according to a translation. "You are the best husband."

Liu's distraught widow told mourners that her husband was "my hero" who "took pride in the fact that he was NYPD."

"To me, he is my soulmate," she said. "Wenjian is an incredible husband, son, coworker and friend, my best friend."

After she spoke, a driving rain began. As she walked out of the funeral home, a tearful Chen clutched her husband's photo.

When NYPD officers presented her with the flag that was draped over Liu's coffin, she bowed.

"I love you. Forever," Chen told mourners.