LOS ANGELES -- Tyler Robinson, the suspect accused of assassinating US political activist Charlie Kirk, has been formally charged with aggravated murder, authorities in the US state of Utah announced Tuesday.

Robinson also faces multiple charges, including obstruction of justice, felony discharge of a firearm causing serious bodily injury, witness tampering, and commission of a violent offense in the presence of a child, Utah County Attorney Jeff Gray told a press conference.

Gray said prosecutors will seek death penalty for the suspect, adding that the bullet that hit Kirk narrowly missed several other individuals.

Kirk, 31, was shot in the neck as he was speaking to a large crowd at an outdoor "Prove Me Wrong" debate at Utah Valley University around midday last Wednesday.

Roughly 33 hours after the shooting, the 22-year-old suspect was apprehended in Washington County, Utah.