Laquan McDonald’s supporters gathered to commemorate what would have been the slain teen’s 21st birthday Tuesday.

McDonald was 17-years-old when he was shot 16 times by Chicago Police officer Jason Van Dyke. Van Dyke was charged with first-degree murder and is currently on trial. He pleaded not guilty and claims he acted in self-defense. Dash cam video shows McDonald was walking away from Van Dyke when he was shot.

On Tuesday, McDonald’s birthday, mourners attended a vigil where they sorrowfully sang “Happy Birthday” and chanted "Slave catchers, KKK, killer cops of today,” reports Al Jazeera.

"Our statement today is that [McDonald's] life matters," said Reverend Marshall Hatch, who helped run the event. "If his life doesn't matter, anybody's life does not matter."

Residents are tense as they await a verdict for Van Dyke’s trial. Memorial attendee Tyshondra Barnes, whose father and cousin were killed by Chicago Police, believes there will be “chaos” if Van Dyke is acquitted.

Activist Jessica Disu doesn’t believe the trial will have a happy ending.

"We personally don't expect justice, the young people that I've been working with and speaking to," Disu said. "This courthouse has not shown us justice."

Hatch believes an acquittal would trigger people who are already hopeless.

"There are parts of the community that are in very desperate straits, and the smallest trigger can really just ignite something that none of us wants to see," he said.

In Tuesday’s court proceedings, the defense showed an animated recreation of the shooting, reports The Chicago Tribune. The video depicts a figure representing McDonald advancing toward Van Dyke’s figure, who had his gun drawn. The video stopped after five gunshots.

Reverend Ira Acree, pastor of Greater St. John Bible Church, said McDonald’s aunt “grimaced” when she saw the video.

Hatch likened the video to a cartoon.

“We were in the court today and did see [the prosecutor] in a cross-examination that absolutely nullified the nonsense of us watching an animated, almost cartoonish video,” Hatch said. “It … literally spewed lies on a dead child.”

Now, check these out:

Jason Van Dyke Begins Trial For Killing Laquan McDonald

Cop Who Killed Laquan McDonald Said He Was Just Doing His Job When He Shot The Teen 16 Times

The Police Officer Who Killed 17-Year-Old Laquan McDonald Is Finally Headed To Court