MEDFORD — A man suspected of grabbing an 18-year-old woman off Union Avenue at around noon Friday and sexually assaulting her made his first court appearance Monday.

MEDFORD — A man suspected of grabbing an 18-year-old woman off Union Avenue at around noon Friday and sexually assaulting her made his first court appearance Monday.

The suspect, Leonardo Guillen-Yanel, 20, initially gave a false name, but Immigration and Customs Enforcement officers identified him using their massive fingerprint database, Medford police said.

Medford police arrested Guillen-Yanel Friday on charges of first-degree kidnapping, first-degree rape and first-degree sodomy. Immigration officials added a charge of being in the country illegally, so Guillen-Yanel remains jailed without bail.

He was arraigned Monday in Jackson County Circuit Court on charges of first-degree kidnapping and attempted first-degree rape. The case is expected to go to a grand jury today for evaluation of those and other charges police suspect him of, officials said.

Guillen-Yanel randomly targeted a young woman he saw walking on Union Avenue, Medford police Detective Sgt. Mike Budreau said. The woman was walking in the 400 block of Union Avenue shortly after noon Friday when she noticed a Hispanic man in a green van following her, a news release on the case said.

Near the intersection of West 11th Street and Union Avenue, the man stopped the van, came up and grabbed the woman, forcing her into the vehicle. He claimed to be an immigration officer, she told police.

He drove to a construction area near South Medford High School and sexually assaulted her. Then, he drove on with her still in the van.

At a traffic light at 10th and Front streets, she jumped out and ran, police said.

"We don't know where he was taking her, but we're glad she never found out," Budreau said.

The woman told family members about the attack and they helped her contact police. She was treated at Rogue Valley Medical Center and released.

Investigators found the suspect's van in the parking lot of Sacred Heart Catholic Church at 10th and Oakdale, then tracked him to an address in the 400 block of J Street, where he was staying, police said.

Guillen-Yanel initially told police his name was Sergio Eduardo Garlindo-Garcia, but couldn't spell Garcia, sparking suspicions that he likely was lying about his name, Budreau said. Federal agents were able to find his fingerprint records associated with the name Guillen-Yanel.

Reach reporter Anita Burke at 776-4485, or e-mail aburke@mailtribune.com.