Nathaniel Manlangit, 26, his black hair cut in a Mohawk, walked into the courtroom at the Hall of Justice in San Jose in chains and handcuffs and stood before Judge Diane Northway.
A public defender representing Manlangit requested more time to prepare the case and Northway agreed to postpone the plea hearing until July 29.
Manlangit is suspected of beating to death 31-year-old Carlos Caloca inside the Sports Authority store at the Great Mall.
Milpitas police said Manlangit and Caloca got into an altercation at the store at about 10:50 a.m. on June 7.
According to police, Manlangit picked up a baseball bat from a store shelf and struck Caloca several times.
Prosecutors are still working to piece together what actually happened and what the relationship was between the two men, Deputy District Attorney Angela Bernhard said.
Caloca was hit multiple times with the bat, but the medical examiner's report has not yet been completed, she said.
Manlangit, who is ineligible for bail, has been charged with murder with use of a deadly weapon, and could face 25 years to life in prison if convicted, Bernhard said.