The trial of American Karmelo Anthony has been marked by black demonstrators and lawyers claiming that Anthony killed an opposing athlete in self-defence.

The killing took place before a sporting event at a high school in Frisco, Texas. Outside the courtroom, a group can be heard loudly chanting: “Self-defence is not a crime,” writes Breitbart News.

In April last year, Anthony allegedly argued with football player Austin Metcalf, whereupon he suddenly pulled a large knife from his gym bag and stabbed the unarmed Metcalf in the chest, causing his death. Metcalf was unarmed.

COLLIN COUNTY- Pro-Karmelo Anthony protesters are chanting “self-defense is not a crime” outside of the Collin County courthouse where Anthony’s criminal trial is underway.

They’re wearing shirts with Anthony’s face on them that read “We decree…he is free…Karmelo Anthony”… pic.twitter.com/jEAqJKyU2X

— FRONTLINES TPUSA (@FrontlinesTPUSA) June 3, 2026

What is being described as self-defence is unlikely to be accepted by the court. So-called supporters of Anthony have also threatened white Americans who have attended in support of the murder victim Austin Metcalf, who was 17 years old when he was killed.

17-year-old Austin Metcalf was killed. Still image: WFAA

Witnesses say that it was Anthony who approached the opposing team’s tent and started the disturbance. One witness claims that Anthony was asked to leave the team’s tent at least 15 times before the fateful confrontation that led to Metcalf’s death.

A 17-year-old witness, who attended Frisco Memorial High School with Metcalf, claims that he was among several other Memorial students who were inside the team tent when Anthony entered the team’s area wearing the uniform of his own school, Frisco Centennial.

“You probably shouldn’t be here, you need to leave our tent,” the 17-year-old claims that his teammates began telling Anthony.

“Touch me and see what happens,” Anthony allegedly replied.

Entering an opponent’s tent carrying a knife, refusing to leave after at least 15 requests, and then killing a member of the opposing team – this, the demonstrators claim, constitutes self-defence. They may have been inspired by Anthony’s lawyers, who are making the same argument in court.

The argument is said to have continued for a couple of minutes before Metcalf allegedly gave Anthony a slight shove. Anthony then pulled out the knife he had brought with him and killed Metcalf.

Anthony’s lawyers nevertheless maintain that it was self-defence and argue that the teenage suspect was defending himself against the unarmed, white football player.

Since Anthony was 17 years old when the incident occurred, he cannot be sentenced to death under Texas law, but faces a prison sentence of between 5 and 99 years, or life imprisonment, if he is found guilty.

The victim, Metcalf, has already received his death sentence.