"I think somebody did something to her," Martin said Friday, as police searched the nearby Jordan River for clues in his stepdaughter's disappearance. "She wouldn't just disappear and not come back around. Not this long."
No one has seen or heard from Williams since March 6, 2002, when she dropped off some belongings at a relative's house and said she would return to the home near 1700 South and West Temple.
Her family has struggled in the 12 years since as they wondered what happened to the woman they loved and if she would ever come back.
"There's always that hope that she is going to walk through the door," said sister Lovoina Ortega, who gathered with her family near the banks of the river just days after Salt Lake City police reopened her sister's missing-person case.
Detective Cody Lougy said that several credible tips led them to the riverbank, but he would not describe the nature of the information. Lougy said the case was reopened because of the tips.
"We never forget about these cases," he said.
Lougy said crews combed the area near 2590 S. 1160 West for several hours, with detectives searching on the ground and from above using a helicopter.
Divers searched the river earlier this month, but didn't find anything, according to police.
Police are asking for anyone who knew Williams in 2002 and may have any information about her disappearance no matter how minor they believe the information is to call them.
"If anyone knows anything, just come forward," Ortega said. "Whether good or bad. Just give us some closure. [Let us] bring her home and bury her or whatever."
Martin said that his missing stepdaughter was "so cool." She loved playing video games and going camping. He said Williams also struggled with drug abuse, and he believes that may have played a role in the disappearance.
"She wasn't a perfect person," he said, "but she was a real sweet girl."
Williams' family reported her disappearance in May 2002. She is black and 5 feet 2 to 5 feet 4 inches tall. When she disappeared, she weighed 140 pounds, had pierced ears and a pierced tongue. The name "Shawn" was tattooed on her wrist.
Anyone with information may call 801-799-3000. Anonymous tips may be sent by texting the keyword TIPSLCPD plus any relevant information to CRIMES 274637. The case number is 02-79626.