Demoratic presidential hopefuls Hillary Clinton and Bernie Sanders have both released statements denouncing the 2014 police shooting of 17-year-old Laquan McDonald in Chicago.

Video footage of McDonald's death was recently released, more than a year after he was fatally shot by a Chicago police officer on Oct. 20, 2014. From a police officer's dash cam video, the African-American teen is seen walking in the middle of a two-way street, when multiple police cars drive toward him. Then, just six seconds after arriving on the scene, police officer Jason Van Dyke jumps out of his vehicle and fires 16 bullets at McDonald, who was armed with a knife and had PCP in his system, according to a criminal complaint filed in Cook County Circuit Court.

The video was released after a court judge decided in favor of a freelance journalist who sued the Chicago Police Department, demanding that the video be released to the public. Van Dyke was also charged with first-degree murder just hours before the video was released.

In a statement released on Twitter on Wednesday, Clinton called for justice for McDonald and questioned whether some communities are being protected and respected.

"The family of Laquan McDonald and the people of Chicago deserve justice and accountability. As criminal charges proceed, in this case, we also have to grapple as a country with broader questions about ensuring that all our citizens and communities are protected and respected," she wrote. "The loss of so many young African Americans taken too soon should reaffirm our commitment to press forward for progress."

Meanwhile, Sanders also issued a powerful statement on Wednesday demanding criminal justice reform.

"All Americans should be sickened by the video of Laquan McDonald's murder," the Vermont senator said. "As a nation, we must do more than just echo the phrase Black Lives Matter. We must put actions behind those words. Actions that will bring about the fundamental reform that is needed in the face of this crisis. Criminal justice reform must be the civil rights issue of the 21st century and the first piece must be putting an end to the killing of African Americans by police officers."

McDonald's death sparked a string of protests in Chicago, as activists demanded an end to the use of excessive force by law enforcement officials.

Before the shooting death of the troubled teen, documents show that Van Dyke had a history of complaints during his 14 years as a police office, mostly involving excessive force. At least one complaint indicated he had used a racial slur, reports CNN. However, the white cop was cleared in almost every case.