(CNN) —  

Democrats honored fallen police officers with a moment of silence Thursday night and appearances by family of those killed in the line of duty at their national convention.

The tribute, in the lead-up to the marquee address by Democratic presidential nominee Hillary Clinton on the final evening of the 2016 convention, came after Democrats earlier in the week heard from mothers whose unarmed children were killed by police or died in their custody.

The appearances come as tensions between the police and many African-American communities have soared after killings of both officers and residents.

“I’ve been trying to make sense of it, but violence is not the answer,” Dallas Sheriff Lupe Valdez said Thursday. “Yelling, screaming and calling each other names is not going to do it. Talking within your own group, in your own language, where only your own group understands leads nowhere. We have to start listening to each other.”

Valdez’s comments were delivered just three weeks after five Dallas police were shot and killed by an African-American man who said he wanted to kill white people.

Then, in an emotional display, the family members of slain police officers walked on stage and delivered brief vignettes.

Wayne Lipscomb, mother of slain Philadelphia police officer Moses Walker, described her son’s thoughtfulness. She said that when he was shot and killed, in August 2012, he already had purchased Christmas presents for his friends and family for that December.

“Moses didn’t live long enough to give all of the gifts he had to give. While we’re here we must do all the good we can,” Lipscomb said, before pivoting to Clinton’s message for Thursday night: “We have to believe that we’re stronger together.”

The Dallas sheriff and the family members received long, standing applause from the crowd.

On Tuesday, mothers of African Americans killed by police or gun violence delivered their emotional plea for Clinton.

“Mothers of the Movement” – a group including the mother of Sandra Bland, who died in police custody after being detained in a traffic stop – joined with former Attorney General Eric Holder to call for policing reforms.

The balance that Democrats have been seeking this week on the hot-button issues of gun violence, police brutality and the targeting of law enforcement contrasts with the Republican Convention in Cleveland last week. There, GOP leaders stood firmly on the side of police.

Donald Trump, who diverged from his scripted remarks only a handful of times during his speech accepting the Republican nomination last Thursday night, paused at one point in his address to ask the receptive crown, “How great are our police?”