Holly Ratchford still can't believe that the man she brought home would be accused of being involved in one of America's darkest days.
"It's almost impossible for me to understand who he said he was and who he really was. I still struggle with that to this day," Rachford tells the BBC.
The name of the person we are mentioning was Omar al-Bayoumi. Umar was a resident of Saudi Arabia. His age was around 40 years.
In September 1999, he moved with his family into a housing complex overseen by Ratchford in San Diego, California.
The new tenant, who moved into flat number 152 at Parkwood Apartments, soon became a regular at Ratchford's pool parties.
"He was always very cheerful, had a smile on his face, and was very friendly," recalls Ratchford.
A few months later, Bayoumi introduced Ratchford to two seemingly ordinary people who would later become his neighbors.
These two men became infamous for hijacking American Airlines Flight 77 and crashing it into the Pentagon during the 9/11 attacks.
For the past 25 years, Ratchford has been haunted by memories of her relationships with these three men. He believes that Bayoumi deceived him from the beginning.
"Whenever I held a party, he would come and be a part of the activities," she recalls.
She says that Bayoumi's family often invited her to their home for dinner. “I loved going there,” he said.
But Bayoumi, a former resident of flat number 152 in Parkwood, is now at the center of a $1 trillion (733 billion pound) lawsuit filed against Saudi Arabia by thousands of families of 9/11 victims and survivors.
On September 11, 2001, 19 members of the Islamic extremist network al-Qaeda hijacked four passenger airliners. The attackers crashed these planes into the Twin Towers of the World Trade Center in New York and the Pentagon building in Washington.
Bayoumi is accused of helping in carrying out the 9/11 conspiracy. He provided assistance to the first two hijackers to reach the United States, Nawaf al-Hazmi and Khalid al-Mihdar.
A federal judge in New York hearing a lawsuit filed by the families of 9/11 victims had found a year earlier that the available evidence "leads to a reasonable conclusion" that Bayoumi and a Saudi diplomat stationed in the United States "were in 'continuous contact' with the Saudi government while assisting the hijackers."
This decision of the judge has given permission to proceed with the case of the victims' families. Saudi Arabia is appealing the decision and, along with Bayoumi, has always denied the allegations.
Ratchford saw him talking to and helping the kidnappers. She has given her statement regarding this in the New York court, which is still sealed.
Finding Holly Ratchford was not easy. After 9/11, she started living far away from human population. I located them in the high desert region of the western United States, known as rattlesnake territory.
She told me that she stays away from news and does not talk to journalists. Despite this he agreed to talk to me.
His interview with me raises questions about the story of events that Bayoumi told the police, the FBI and the New York court.
It features in BBC Radio 4's podcast Intrigue: A 9/11 Story and BBC Panorama's upcoming documentary 9/11: The Saudi Connection.
By the beginning of 1999, Ratchford's life was back on track. She became the new property manager of Parkwood Apartments, located in the suburbs of San Diego.
She says that she did her work properly. The houses never remained vacant for long. Actually, this was his dream job and the reason behind it was not because of the paper work or good salary but because of the people there.
Omar al-Bayoumi had come to live in Parkwood claiming that he was a mature student. "I knew he was studying," Ratchford says. What else he did, I can't say for sure."
FBI documents declassified more than two decades later and court filings reveal that Bayoumi's studies had actually almost stopped in 1998. He spent most of his time organizing religious activities in the Muslim community.
Richard Lambert, who led the FBI's investigation in San Diego after 9/11, tells me, "The general belief in the Muslim community of San Diego was that Bayoumi was an operative of the Saudi secret service."
The FBI later learned that he was being paid approximately $90,000 annually.
Bayoumi presented himself as an ordinary family man. The Bayoumi that Ratchford saw was captured in a never-before-seen home video.
In the summer of 1999, Bayoumi filmed the US Capitol building in Washington DC from different angles. In the video he mentions a "plan" and then turns the camera towards himself and comments like a reporter.
Lawyers for the families of 9/11 victims allege that he was conducting a recce of the building as a possible target for the attacks. Saudi Arabia says it was a tourist video.
On February 3, 2000, Bayoumi brought two young men to Rachford's rental office in San Diego. He was clearly in a hurry. He told that these two men were from his mosque and were staying with him while he was looking for a place to live on rent.
She recalls, "There was nothing strange about him. He was nice and well-mannered." Neither of the men spoke English, but Omar al-Bayoumi took up the responsibility.
Ratchford had some rules. He immediately refused. But both men had several thousand dollars in cash. The next day, Bayoumi took him to a nearby bank and helped him open an account, bank records show.
On the third day in Ratchford's office, he came up with a solution to the difficult income condition. He was going to co-sign her lease agreement, that is, he was going to become the legal guarantor for her apartment.
There are many signatures of Bayoumi on the rental agreement. He was her guarantor, her friend and emergency contact, and his Parkwood home was listed as his current address.
The names of the two men who were taking legal responsibility for Bayoumi were Nawaf al-Hazmi and Khaled al-Mihdar. Both of them were later to become hijackers of 9/11.
Holly saw both of them several times over the next few months. She says, "I used to have tea and biscuits with him. He was not the kind of person who just came to the office and rented space from us."
Hazmi and Mihdar lived in their apartment until the end of May that year and then moved out. Ratchford didn't think much about it.
When America was in shock and grief after the 9/11 attacks, a woman called him and asked for rental references for both of them. Without thinking, he gave their information. But that woman was not a property agent, she was a reporter.
Her next question shocked Ratchford, "Did you know he was one of the two terrorists who flew his plane into the Pentagon?"
On September 14, 2001, two special agents interrogated Ratchford in his office in Parkwood. He gave Omar al-Bayoumi's guarantor form to the FBI.
"As we began to identify the hijackers' accomplices, it became clear that there was a network led by Omar al-Bayoumi," says Richard Lambert.
The FBI discovered that Bayoumi's contacts had helped Hazmi and Mihdar obtain California driver's licenses, apply to flight schools, receive money from the Middle East, and even arrange dental treatment.
On 21 September 2001, the Anti-Terrorist Branch of the Metropolitan Police arrested Bayoumi and began interrogating him. Unperturbed and sometimes expressing anger, Bayoumi initially denied knowing any of the hijackers.
A day later, he said he remembered helping two people, 'Nawaf' and 'Khalid'. He admitted that they were the only two people to whom he had given such help.
Bayoumi claimed that he met them both in Los Angeles, when he overheard them speaking Arabic in a restaurant.
According to Bayoumi's statement, his contact with the future hijackers was very short-lived. But his story does not match Ratchford's version of events.
"I know that's what he said, and I know it's bullshit," Ratchford says.
Ratchford says that before bringing the hijackers to her office, Omar al-Bayoumi had asked her several times about finding an apartment for two people.
She also refutes Bayoumi's claim that she rarely saw the hijackers after getting the apartment, saying that Bayoumi saw them together in the weeks that followed. Once all three of them even came to his office for tea and cookies.
British police detained Bayoumi for seven days. The US Justice Department decided not to extradite Bayoumi to face charges. Bayoumi was released on 28 September 2001.
San Diego agents discovered that two companies linked to the Saudi Defense Ministry were paying Bayoumi a salary of $90,000, but he never went to work and spent "exorbitant amounts."
The FBI found letters written to a charity associated with the Saudi government that had direct ties to al-Qaeda. They also found some documents written by Omar al-Bayoumi himself that could be considered "jihadi-oriented".
Omar al-Bayoumi left the UK for Saudi Arabia in August 2002.
