Samuel Lincoln Woodward, 20, has been arrested in connection with the death of Blaze Bernstein.
A high school friend accused of killing a University of Pennsylvania student and dumping his body at a California park previously made "violent" comments online and defended the Confederate flag, a report said. "When we stop crying we will start doing positive things to affect change".
Bernstein, who was a student at the University of Pennsylvania (UPenn), was staying at his family's home during the winter break.
Bernstein's body was found Tuesday in brush surrounding the park.
Friends and strangers have created a makeshift memorial for Blaze Bernstein in the park where he was killed.
This undated photo provided by the Orange County Sheriff's Department shows Blaze Bernstein, 19, as they seek the public's help in finding him. "Stop being complacent. Do something now".
Orange County Undersheriff Don Barnes told reporters last week that investigators quickly focused on 20-year-old Samuel Lincoln Woodward, who, they say, had been talking to Bernstein on Snapchat the night he disappeared. That is what Blaze would want.
Mourners embrace as they join more that 300 people in Borrego Park in Foothill Ranch, Lake Forest on Wednesday, Jan. 10, 2018 for a candlelight vigil for Blaze Bernstein. "We have seen this first hand in the tremendous amount of support we received from people everywhere".
Bernstein's death rocked the tight-knit community 50 miles (80 kilometers) southeast of Los Angeles. "Blaze was on a path to fix our world and it is a moral imperative that we all take steps now to make sure that his dream is realized".
Woodward told investigators he left the park after Bernstein didn't return or respond to social media messages he sent him. The Orange County coroner's office said Monday that the cause of death remains under investigation.
Bernstein, a sophomore, was planning to major in psychology and later study medicine, the Orange County Register reported his father, Gideon Bernstein, saying last week. He had recently been named to the staff of Penn Appetit magazine at school. According to the Register, they attended the Orange County School of the Arts in Santa Ana, California. He went back to the park less than two hours later, but Bernstein was still nowhere to be found.
Investigators also noticed several scratches and abrasions on his hands which he claimed were from a "fight club". He allegedly could not remember the last name of the girlfriend he said he had left to see late that night. He also appeared to have dirt under his fingernails.
Orange County Undersheriff Don Barnes told the Los Angeles Times that sheriffs had used Bernstein's Snapchat account to determine that the young man had gone to the park with his high school classmate Woodward on the night of January 2. He has not yet been officially charged but is in custody, Braun told ABC News.