LOS ANGELES (AP) — Four teenagers have pleaded not guilty to murder charges in the fatal beating of a 24-year-old University of Southern California graduate student from China.

Los Angeles County District Attorney spokeswoman Sarah Ardalani says that 19-year-old Jonathan Del Carmen, 18-year-old Andrew Garcia, 17-year-old Alberto Ochoa, and 16-year-old Alejandra Guerrero, entered their pleas Tuesday in a downtown Los Angeles courtroom.

Prosecutors allege the four attacked and beat USC engineering student Xinran Ji at around 1 a.m. on July 24 as he walked home to his south Los Angeles apartment.

Prosecutors have not yet decided whether to seek the death penalty against Del Carmen and Garcia.

Garcia and the two younger teens were also charged with robbery and assault.

All four are due back in court on Sept. 12.

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