The shooting of an unarmed African American student by a police officer in Ferguson, Missouri, on Aug 9 has dented the self-proclaimed human rights pride of the United States.

Michael Brown, 18, was walking with a friend to his grandmother's house when police stopped him for questioning regarding an "armed robbery" at a convenience store. Since police officer Darren Wilson treated Brown as a suspect, a quarrel broke out between the two. This enraged Wilson, who started shooting at the teenager and his friend - a later video showed 11 shots were fired, six of which, including two deadly ones in the head, hit Brown.

A CNN video telecast on Aug 12 showing some police officers yelling "Come on, you beasts" at the protesters added proof that racism is still a fact of life in the US. Repeated protests aroused concerns of the general public as well as US President Barack Obama. During his summer vacation, Obama expressed sympathy for the "passions and anger" sparked by the death of Brown.

The US government tried to restore normality through varied means, including flying the national flag at half-mast in the summer, but failed to stop people from discussing the causes of such tragedies in the US and the lessons that could be learned from them.

Many American citizens believe only "accidental factors", such as the accidental abuse of power by a police officer or the shooting of a black man by a white police officer, constitute "racism and racial contradictions" in the US. They also believe the political parties - which used the Brown tragedy to express their political positions in a bid to win support for the 2016 presidential election - also played a role in fuelling the protests. But by holding "accidental factors" responsible for the protests, these American citizens have failed to grasp the real reason behind the "human rights crisis" in the US.