Organizers of the Disarm Hate rally expect as many as 10,000 people to attend, but few national leaders of the two causes.
Homeless ex-convict Linda Thompson told a judge going back to prison would be like going home, and asked for a 10 year sentence.
Demonstrators scuffled with police outside the Quicken Loans Arena, preventing some attendees and journalists from entering the convention.
In an interview with Fox News anchor Bill O'Reilly, Trump declares if elected he'll task his attorney general to monitor the group, cofounded by two queer African-American women.
Jesus Retana, a police officer for Dallas's transit system, was one of seven law enforcement officials injured by a sniper on Thursday; five died.
"He was upset about Black Lives Matter," Chief David Brown said, adding that the gunman cited this week's killings of two black men by police in Louisiana and Minnesota.
The morning after the single most deadly attack on law enforcement since 9/11, the mayor and police chief of Dallas and President Obama denounced the deadly ambush.