As dozens of people gathered in Harlem on Sunday to honor two slain New York police officers, President Obama expressed his condolences and the president of the NAACP decried the gunman's claim that he was avenging two unarmed black men who died in confrontations with police last summer.
Young women sang, "This Little Light of Mine" at a candlelight vigil for officers Wenjian Liu and Rafael Ramos, who were shot to death Saturday in Brooklyn. Police say Liu and Ramos were ambushed by Ismaaiyl Brinsley, who killed himself as police pursued him.
At the vigil, demonstrators voiced support for law enforcement and carried signs that said, "Claim humanity," "Imagine justice," "Claim love" and "We are human." Some of the participants had also joined protests over the July death of Eric Garner in a confrontation with police, and over a Staten Island grand jury's refusal to indict the officer involved.
"I'm here because all life is valuable and all life matters," Elle Green, a 38-year-old social worker, told the Los Angeles Times.
Green said at a time like this it was important to build trust and safety in the community and to nurture a positive relationship with the police.
"Just because you're angry doesn't mean you're anti-law enforcement," she said, referring to the anger over Garner's death.
Another demonstrator, the Rev. Stephen Phelps, said those who had participated in the Garner demonstrations were devastated by the officers' slaying.
"Our hearts were broken," Phelps told The Times. "We want to see changes, but at the same time, we want the police to know that we support them. We want the police to know that we want to work with them."
Other vigils took place at the scene of the shooting, in Brooklyn, and in front of Ramos' childhood home.
In Hawaii, the vacationing Obama called New York Police Commissioner William Bratton on Sunday.
"The president reiterated his call for the American people to reject violence and words that harm, and turn to words that heal -- prayer, patient dialogue and sympathy for the friends and family of the fallen," White House spokesman Eric Schultz said in a statement.
Before killing the officers, Brinsley posted on Instagram: "I'm putting wings on pigs today. They take 1 of ours, let's take 2 of theirs." He hashtagged the names of Garner and Michael Brown, an unarmed black man killed by police in Ferguson, Mo., in August.
Cornell William Brooks, president of the NAACP, said it was unfair "to link the criminal insanity of a lone gunman to the peaceful protests" over grand juries' refusal to indict white police officers in the killings of Garner in New York and Michael Brown in Ferguson, Mo.
"The fact of the matter is, in this country, we have a violence problem," Brooks told CBS' "Face the Nation." "Think about it this way. The tears of the families of these police officers and the tears of Eric Garner's family and Michael Brown's family aren't shed in law enforcement blue, racially black or brown. They're colorless. They're tragic and unnecessary."
The Rev. Al Sharpton, one of the forces behind protests over the killings of Garner and Brown, echoed that sentiment.
"This is a pursuit of justice to make the system work fairly for everyone," he said at a news conference. "This is not about trying to take things in our own hands. That does not solve the problem of police misconduct."
Using Garner's and Brown's names in such a context is "hurting the cause of these families," Sharpton said.
Garner's mother, Gwen Carr, and his widow, Esaw Garner, joined Sharpton and expressed their sorrow for the officers' families.
"These two police officers lost their life senselessly. Our condolences to the family, and we stand with the family," Carr said.
Esaw Garner delivered a message to demonstrators: "Please protest in a nonviolent way. My husband was not a violent man, so we don't want any violence connected to his name."
Srikrishnan reported from New York, Stewart and Raab from Los Angeles.