PORTLAND, Ore. (KOIN 6) — When police went to search an accused murderer’s apartment in Bellevue, Wash., they looked for photographs of the woman they say he killed, diaries, notes, logs, and receipts that could put the alleged killer inside the DoubleTree Hotel.

Later, when Tae Bum Yoon was caught after Portland detectives spent days following evidence on his and the victim’s cellphones, he reportedly asked them a pointed question.

“How did you find me?” Yoon inquired, according to court documents.

Bellevue Police Officer Gregory M. Grannis writes in the documents that Portland Police homicide detectives Michele Michaels and Bryan Steed informed his department that Yoon was identified as the primary suspect in the homicide of Ashley Benson. Her body was found Dec. 26 in the DoubleTree Hotel in Northeast Portland near the Lloyd Center Mall. Police said she was a victim of human sex trafficking.

According an affidavit filed this week in King County Superior Court, Yoon may have committed the crime of identity theft by going to the DoubleTree Hotel and accepting a reservation that had been made under the name of “Chris Youn.” According to detectives, that is a real person who lives in Washington.

Yoon, court records show, arrived in Portland on Dec. 25. He went to the hotel and pretended to be Chris Youn, though he changed the reservation to match the spelling of his name and paid in cash, court documents state.

The front desk employee working at the time said Yoon came in around 9 p.m. and said he had a reservation for the next day but wanted to check in early. The man, court documents show, was asking if he could keep the same discount rate.

Benson was working as an escort, according to court records, and met with Yoon in his hotel room. The two had met before, the records suggest.

According to records, the real Chris Youn arrived at the hotel on Dec. 26 and was questioned by police. They determined he had nothing to do with the homicide. He told police that he was a DJ who came down to Portland to perform on Dec. 26, and had no idea how Yoon had learned he was staying at the hotel, court records show.

Yoon left the hotel, and Benson’s body was found in the stairwell on the eighth floor, according to Detective Steed, who filed a separate affidavit in Multnomah County Circuit Court. When Benson’s body was found, it was discovered just inside the stairwell door. “There appeared to be marks on the neck of the deceased female. No shoes or socks were on the body,” Steed wrote. He went to a different hotel where he tried to rent a room, but the hotel would not accept cash, records show. A taxi driver took him to a motel in Beaverton. Court records show that when he approached the counter at the hotel that did not accept cash, the clerk noticed injuries to Yoon’s body and asked what happened. He reportedly told the employee that he was in a fight and was trying to get away, court records show.

According to Deputy Medical Examiner Damon O’Brein, Benson died of homicidal violence by strangulation, court documents state. An autopsy by Dr. Karen Gunson confirmed the initial assessment by O’Brein, court records show. Police on scene used a portable fingerprint machine to confirm Benson’s identity.

“How did you find me?” Yoon inquired, according to court documents.

On Dec. 30, 2014, police in Bellevue started doing undercover work tracking Yoon.

Eventually, police in Washington learned that Yoon was living in an apartment building called “TEN20.” By Jan. 7, Detective Michaels and Portland police had obtained a warrant from T-Mobile, Yoon’s cellphone provider, and soon realized their suspect was back in Portland. He was taken into custody at Union Station. Police were able to find Amtrak ticket sales, court documents state.

Police started to question Yoon, who acknowledged his address in Bellevue, Wash. where police were securing the residence for a later search, court documents state. When police seized a phone on Yoon at the time of his arrest, it reportedly showed “significant cocaine trafficking,” court documents state.

Michaels spoke with a hotel employee who said she had received three phone calls from an anonymous woman worried about her friend who had met with a person and who had agreed to go to his room which was 715, court records show. The caller had not heard from her friend and was concerned for her welfare, Steed wrote. On the final call, the person told the employee that her friend was supposed to me a person named Chris Yoon, court records show.

A printout of room 715 showed the hotel room had been rented out to “Chris Yoon,” documents show. There were several phone calls to a Washington phone numbe used in advertisements for escort services.

Police found multiple images of a female matching the description of Benson and found photos on the websites EscortProfile.xxx and TNA.com that matched the unique tattoos she had, court records show. On the TNA.com website, Benson is posting under the name “Foxxy.Veronica” and was using a Yahoo email account, court records show.

During a search of the phone, there was an email between Benson and “chrisyoon1990@hotmail.com.” Part of the email read, “Let me make this clear before you read my message. You WILL be COMPENSATED for all the time you invested in me. I have every intention of PAYING you…Before you blame me 100%, I want you to know that you did break our agreement. You did post and although I forgave you, I did find new listings in Houston texas backpage,” according to court documents.

Detectives spoke with Benson’s boyfriend and learned that Benson had once told him about a man named Chris Yoon. She had met Yoon on more than one occasion, she said, and the 24-year-old had given her large sums of money for doing nothing at all, the records show.

When police seized a phone on Yoon at the time of his arrest, it reportedly showed “significant cocaine trafficking,” court documents state.

Yoon reportedly told detectives that he called Benson because it was difficult for him to meet female friends. He said their relationship turned into that of one being “good friends,” Steed wrote in court documents. According to cell phone records, Yoon had sent or received more than 25 text messages from Benson’s phone on Christmas Day.

Police in both states said there is enough evidence found to show that Yoon has been involved in a high level cocaine trafficking operation. Records in King County show his apartment was being rented for $3,000 a month. BPD said they do not have any evidence that Yoon has a full-time occupation.

Yoon has entered a not guilty plea to a single count of murder.

He is expected to be in court next week following a grand jury review of the evidence collected thus far.