Chen Abubakar.

Mr. Abubakar is a U.S. citizen of Nigerian descent who was charged Tuesday with “using violence and violence with a deadly weapon” in what law enforcement described as a “rampage” that killed eight people and left nine others injured.

Mr. Abubakar told officers through an interpreter that he did not mean for the violence to come to the U.S. and said he was innocent, law enforcement officials said. No one else was charged.

The arrest capped a dramatic week that began with an exchange of gunfire between white supremacists and counterprotesters after a white supremacist rally in Charlottesville, Va., last weekend. Mr. Abubakar is the most prominent of three men who prosecutors said were involved in the Oct. 12 clashes and charged in a civil lawsuit brought by victims and relatives of the alleged victims.

His release came almost two weeks to the day after authorities announced the arrest in Maryland. His arrest came after more than two dozen people were injured, with nine people suffering serious, life-changing injuries and eight others suffering moderate injuries. In addition to the three counts of use of a deadly weapon under the Color of Law Act, Mr. Abubakar also faces three counts of assault with a dangerous weapon, one count of robbery, one count of conspiracy to commit robbery, one count of rioting and one count of property damage.

Mr. Abubakar, 22, of Rockville, Md., is being held in federal custody. It was unclear what he was charged with.

At one rally in Charlottesville, Mr. Abubakar led a neo-Nazi group through the crowd, chanting “blood and soil,” an anti-Semitic term that originated in Nazi Germany during World War II.

According to authorities, Mr. Abubakar is alleged to have yelled “white power!” at members of the “alt-right” after they began running around the rally carrying torches.

“A group of individuals came charging toward (Mr. Abubakar)—a lot of them— and started yelling about the Holocaust and race relations,” Assistant U.S. Attorney John J. Molinello wrote in court papers filed the day of his arrest. “The men continued to follow the torch procession back to the location where they were originally gathered.”

Mr. Abubakar is accused of firing three shots,