JACKSONVILLE BEACH, Fla. -

A 21-year-old Navy sailor made his first appearance before a judge Saturday after he was arrested Friday in Jacksonville Beach. Police said he raped a woman in a random attack.

Edward Marshall-Byrd Jr. is charged with sexual battery with great bodily injury and aggravated battery. The judge ordered Marshall-Byrd held without bond.

The judge also assigned a public defender to represent Marshall-Byrd.

Police said Marshall-Byrd Jr. attacked and sexually assaulted a 24-year-old woman about 3:45 a.m. in the 100 block of First Avenue North. Officers said the woman was on her skateboard going to a friend's house when Marshall-Byrd grabbed her and attacked her in the middle of First Street.

"He attacked her, basically laid hands on her, punched her, hit her, knocked her to the ground, and that's where the sexual assault took place," said Sgt. Mark Evans, of the Jacksonville Beach Police Department.

Police said Marshall-Byrd was located about a block away by officers and positively identified by the victim and two separate witnesses, who called police after the attack.

"When I was in the car, she screamed out, 'Help, I've just been raped,'" witness Alfred Gainer said.

The manager of Jimmy's Chicago Pizza was leaving work around 3:45 a.m. when he saw the woman being attacked. He said a homeless man who also saw the attack flagged him down, and Gainer jumped out of his truck to help.

"I saw there was some guy punching a girl in the head and he got off and ran," Gainer said.

The victim was taken to Shands Jacksonville Medical Center, where she was in stable condition.

Gainer said the victim believes he saved her life.

"She feared for her life," he said. "She told me several times had I not shown up, she didn't think she would make it."

Marshall-Byrd is charged with sexual battery with great bodily injury and aggravated battery. He is a crew member of the USS Halyburton, a guided missile frigate at Mayport.

Beachgoers are thankful for Gainer's quick response.

"That makes me feel better," resident Gabby Loscalzo said. "That makes me feel that we could still come here after hours instead of just during the day time."

"We come out to some of the bars and the grills and we expect to be safe when we come out here," beachgoer Tammy Carter said. "So that's very surprising that would happen out here."

Gainer doesn't call himself a hero. He hopes anyone would do what he did.

"I'm glad she's OK," he said. "I'm glad I was in the right place at the right time. I'm glad I was there to stop her from going through anything else."