If convicted he could be sentenced up to 70 years in prison.
A high school student, Williams made a court appearance late Friday (August 17, 2012) afternoon. The judge set bail at USD 250,000.
The suspect is scheduled to be back in the court on Monday, August 20, 2012.
The deceased Dalbir Singh, 56, assisted his nephew Jatinder Singh in running a grocery store in the city.
The incident happened on Wednesday (August 15) night when some unidentified men entered the shop and put a gun to Jatinder Singh's head.
Jatinder Singh said he and his uncle made it back into the store and pushed the side door shut.
But one of the men fired a shot through the door, killing Dalbir Singh, it said.
Dalbir Singh was a regular visitor to the gurdwara in Oak Creek, but was not present when the tragic incident happened on August 5.
Jatinder Singh had gone to the gurdwara, but had left its premises before the shootout began.
Jatinder Singh told police he saw Williams in the store prior to its closing, saying Williams looked around and left without buying anything. He identified Williams to police through a photo lineup.
The police has said there is no relationship between the killing of Dalbir Singh and the gurdwara shooting on August 5 by a white supremacist that killed six Sikh worshippers.
According to the criminal complaint against Williams, the suspect confronted Dalbir Singh and waved a gun at him.
Dalbir Singh and his nephew, Jatinder Singh, ran inside the store, slammed the door and tried to keep it shut to prevent Williams from getting in.
The complaint indicates that as the Singhs were holding the door, "there was a gunshot from outside the door that penetrated the door and hit Dalbir Singh in the forehead."