“She said she was there for a United Nations friendship event. Well, that was a clear lie,” Assistant US Attorney Rolando Garcia told the jurors during closing arguments Tuesday. “She was bound and determined to get on that property. … She lied to everybody to get on that property.”

Zhang, who did not put on a defence, did declare her innocence during closing arguments, saying she had a contract to attend a United Nations friendship event between the United States and China at the Mar-a-Lago club. “I do think I did nothing wrong,” said Zhang, speaking in English. “I did no lying.”

During the trial in Fort Lauderdale federal court, Zhang spoke occasionally in halting English and in Mandarin to raise an objection or ask US District Judge Roy Altman a question about the government’s evidence. While it was apparent that Altman, a former federal prosecutor recently appointed by Trump to the federal bench, tried to give Zhang a fair trial, it seemed clear Zhang’s decision to fire her assistant public defenders sealed her fate from the outset.

Her trial began in unusual fashion Monday when she showed up in a jail uniform rather than the civilian clothes that had been provided to her. She complained about not having any “undergarments” to wear. Altman allowed her to change into khaki trousers and a blouse, and the trial got under way.

Zhang Yujing: Naive tourist or bumbling spy?

Zhang, who says she is a successful businesswoman from Shanghai, is also under scrutiny from a federal counter-intelligence investigation, although she has not been charged with spying. The secret “national security” investigation – reflected in government evidence that has been filed under seal in Zhang’s trespassing case – never came up at trial.

Evidence showed that Zhang bluffed her way past two security checkpoints before she was allowed to enter Mar-a-Lago after 12pm on March 30. Initially, she told Secret Service agents and club staff that she was going to the pool. Her last name – one of the most common in China – happened to match that of a member, so they let her in.

But a sharp-eyed receptionist thought Zhang looked suspicious when she walked into Mar-a-Lago’s ornate lobby in a long grey evening dress while shooting video with her mobile phone. Zhang breezed past the receptionist, Ariela Grumaz, into a lounge area.

“As soon as she entered the lobby, you could see she was fascinated by the decorations and that is when I realised she had never been here before,” Grumaz testified.

Federal prosecutors based their case on evidence that Zhang knew she had no reason to enter the president’s club and nonetheless lied her way in. Grumaz, the receptionist, proved a valuable witness.

That afternoon at Mar-a-Lago, Grumaz recalled in her testimony, she stopped the Chinese woman and asked for her name. She said Zhang was not on the list of members or guests at the president’s private club. Zhang showed the receptionist something on her cellphone indicating she was attending a United Nations friendship event between China and the United States that evening. But Grumaz said she checked with the catering manager and found there was no such event scheduled.

Zhang had in fact bought a ticket for a Safari Night charity gala originally on the calendar for that evening. But the event had been cancelled a few days before, something Zhang was well aware of at the time, prosecutors argued.

Secret Service Agent Samuel Ivanovich said that he and other agents questioned Zhang in the Mar-a-Lago lobby before escorting her off the premises.

He said that when the agents began to search the electronic devices inside her purse, Zhang “became aggressive in nature”. But she agreed to go to the Secret Service’s West Palm Beach office for questioning, he said.

Ivanovich said Zhang explained during the interview that she made arrangements for her trip to Mar-a-Lago through a man named “Charles,” and that she also planned to visit other parts of the United States. She told him that she only knew Charles through their phone messaging on the “We Chat” social media app popular in China.

The agent said he pressed Zhang about why she initially told the Mar-a-Lago security staff that her reason for coming to the president’s private club was to go to the pool.

“She stated that she did not say that,” Ivanovich testified.

Federal agents later searched her iPhone 7 and discovered that Zhang had received text messages from a man named “Charles,” who told her that the March 30 event had been cancelled days before she left China. But Zhang, who booked her own flight with US$2,000 in cash, flew from Shanghai via Newark to Palm Beach on March 28 anyway, according to trial evidence.

After Zhang’s arrest, agents searched her hotel room and found a bevy of electronic devices, including a hidden-camera detector, along with US$7,600 in US currency and US$600 in Chinese currency.

Assistant US Attorney Michael Sherwin said towards the end of the trial that Zhang’s demeanour throughout her brief visit to Mar-a-Lago revealed that she was determined to get into the club, suggesting she was up to no good.

“It shows she was not a wandering tourist,” Sherwin said, “who fell into this situation by mistake.”

Sentencing is scheduled for November 22.