Omar Abdelbadie entered the not guilty plea in King County Superior Court. His mother was in the courtroom.
Police say Abdelbadie knew the girl was 12 when he talked her into coming to his apartment, gave her marijuana and had sex with her multiple times throughout the night.
Officers were first called to the University District on June 10 just after 8 p.m. when another man called police to report the incident.
The witness told officers he knew Abdelbadie from a previous job and had noticed him Monday evening walking with what appeared to be an underage girl. The witness said he asked the girl how old she was, and she told him she was 15.
He also said both Abdelbadie and the girl admitted to having sex. Because the witness knew Abdelbadie was 21 years old, he called police and held Abdelbadie's phone to keep him from leaving, according to court documents.
When officers arrived moments later, Abdelbadie told them he was walking along University Avenue the previous night when he saw the alleged victim. He said she was dressed provocatively, and when he saw her walk by again he decided to talk to her, according to police.
Police say he admitted to "hooking up" with the girl and knowing her real age, but when asked how old she was, he said, "I plead the fifth."
The alleged victim, who was reported missing Sunday night, also said she told Abdelbadie that she was 12 years old. She told officers she met Abdelbadie late Sunday on the Ave and agreed to go to his apartment. She said Abdelbadie gave her marijuana and they had sex.
Police arrested Abdelbadie on suspicion of child rape. He is being held on $100,000 bail.