BALTIMORE, April 26 (UPI) -- The demonstrations set off by the death of Freddie Gray have been mostly peaceful, but some Baltimore residents have seized the opportunity to protest violently.
At least 12 people have been arrested. Windows of police cars and stores have been targetted by violent protesters. Baltimore Mayor Stephanie Rawlings-Blake condemned "agitators" who generated the violence, stating she was "profoundly disappointed."
Rawlings-Blake spoke alongside Gray's twin sister, Fredericka.
"My family wants to say, 'Can y'all please, please stop the violence,'" Fredericka said. "Freddie Gray would not want this."
Baltimore Police Commissioner Anthony Batts commended the efforts of peaceful protesters who tried to defuse the situation.
"Don't lose the message!" a protester said to an enraged crowd. Batts thanked peacemakers.
"Residents put themselves in between police officers and agitated crowd and asked for calm and asked for peace, which was very good to see," he said.
The protests happened soon after Baltimore Police Department acknowledged it failed to get Gray, a 25-year-old man, prompt medical attention for a spinal cord injury while in police custody.
Gray was arrested April 12 after running from police. He was tackled to the ground by police, handcuffed and dragged to a police van. A bystander recorded the arrest on a cellphone.
Gray died a week after his arrest. Family members said his spinal cord was 80 percent severed and his voice box was crushed.
Malik Shabazz, a founder and the president of Black Lawyers for Justice, has demanded the arrest of six officers involved in Gray's death. The officers are suspended with pay while under criminal investigation by the police department.
The U.S. Department of Justice is reviewing the case for possible civil-rights violations and the Gray family is conducting its own investigation.
Funeral services for Gray are scheduled for Monday at New Shiloh Baptist Church in West Baltimore.
Amy R. Connolly contributed to this report.