Caleb McGillivary, 24, was being held in a New Jersey jail after he waived extradition following his May 16 arrest in Philadelphia. He is charged with beating 73-year-old lawyer Joseph Galfy to death after they met in New York City. Galfy's body was found in his Clark, N.J., home.
When a reporter asked if the killing was self-defense, McGillivary responded Thursday: "I don't know. You tell me."
McGillivary, wearing a T-shirt and jeans and sporting a scruffy hairdo and long sideburns, was escorted by sheriff's officers into the Union County jail on Thursday morning.
He said he had been advised by his public defender not to say much, but added; "I'd just like to say 'thank you' to all the supporters."
McGillivary gained a dose of fame in February when he was interviewed after he intervened with a hatchet in an apparently unprovoked attack on a Fresno, Calif., utility worker.
Union County Prosecutor Theodore Romankow said the case was still under investigation and police were still gathering forensic evidence.
McGillivary is expected to be arraigned in New Jersey next week, Romankow said.