LOS ANGELES (AP) -- Three of four teens charged with fatally beating a Chinese graduate student at the University of Southern California last year appeared in Los Angeles County Superior Court for a hearing Tuesday to determine if they will face a murder trial.

The defendants are charged with killing Xinran Ji, 24, as he walked home to his apartment near campus after studying with other students.

Authorities allege Jonathan Del Carmen, 19; Andrew Garcia, 19; Alberto Ochoa, 17; Alejandra Guerrero, 16, were trying to rob Ji when they beat him with a bat and wrench and left him for dead. Ji was able to make it to his apartment, where a roommate found him dead in bed in the morning.

Alberto Ochoa, left, appears in Los Angeles Superior Court Monday with his attorney Christopher C. Chaney. (AP Photo/Los Angeles Times, Al Seib, Pool)

Photos displayed at the hearing showed Ji lying in his bed in what appeared to be a blood-stained shirt and pants. Puddles, droplets and smears of what looked like blood were found throughout the apartment.

Los Angeles Detective Matthew Courtney said he and his partner followed a possible trail of blood from the apartment, down the street and around the corner.

The July 24 killing renewed criticism about the safety of Chinese students at USC. China's consulate general said it was concerned about student safety at the campus.

The school and Los Angeles police beefed up patrols on and around campus after two Chinese graduate students were murdered outside an off-campus apartment in 2012. The university is surrounded by historically high-crime neighborhoods.

Until last year, USC had recruited the highest number of foreign students in the country for more than a dozen years. It dropped to No. 2 behind New York University, according to a survey by the Institute of International Education, though it remains very popular with students from abroad. About 40 percent are from China.

Ji enrolled at the university in 2013 after excelling at one of China's best universities, where he won a prize for mathematical modeling.

After Ji's beating, three of the suspects went to the beach and tried to rob a couple, police said.

Del Carmen and Garcia could face the death penalty if convicted. Ochoa and Guerrero are charged as adults but can only face up to life in prison without the possibility of parole if convicted because of their ages. All four are being held without bail.

Proceedings against Garcia were postponed because his lawyer was ill and questions were raised about his mental competency. Garcia blurted out obscenities in court Monday at the end of a brief hearing.

© 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Learn more about our Privacy Policy and Terms of Use.