The FBI’s kidnapping case against a Florida man, whose estranged wife disappeared in Spain in February, shows she thought he was monitoring her and that investigators believe he used his Colombian girlfriend to translate fake text messages from her into Spanish.

David Knezevich, 36, was arrested over the weekend, after returning to the United States from his native Serbia, in connection with the disappearance of Ana Knezevich in Madrid on 2 February.

Court documents unsealed on Monday and seen by The Independent have revealed more details of what the FBI believes happened to Ms Knezevich.

The US citizen had travelled to Madrid from Miami on 26 December, where she lived for nearly two months and stayed in touch with her friends and family back home before they lost contact with her on 2 February.

She had left the US after separating from her husband of 13 years who “did not want to split the marital assets evenly” with her, the FBI said.

“The victim was very fearful of Knezevich and believed that he was surreptitiously monitoring her whereabouts,” the documents said.

Ms Knezevich’s last known movements include a credit card payment for flowers on or about 2 February, as well as security camera footage of her entering her apartment building at around 2.20pm that day.

The FBI says she was not seen alive again.

Friends received suspicious texts

On 3 February, two of the victim’s friends received strange text messages from her, explaining that she was running off for a few days with a man she had just met.

“I met someone wonderful”, the message said in Spanish. “He has a summer house about 2h from Madrid. We are going there now and I will spend a few days there.

“There is barely any signal though. I’ll call you when I come back. Kisses.”

The message also said that she had gone for a walk after therapy, a man had approached her to flirt and they had an “incredible connection”, again in Spanish.

Her friends flagged these messages to law enforcement, saying they did not think Ms Knezevich had written them.

Those messages were allegedly the result of Mr Knezevich asking his Colombian girlfriend for help in translating a message in English into “perfect Colombian”.

He claimed that he needed help translating some lines for a Serbian friend who was writing a script about a Colombian character.

The girlfriend, referred to as “Individual 1” in court documents, had met the suspect online in October 2023. She called law enforcement when her mother saw a news article about Ms Knezevich with a text message matching the one her daughter had translated for the suspect.

Suspect drove thousands of miles to Madrid

Investigators allege that Mr Knezevich left Miami on 27 January and travelled to Istanbul, Turkey, where he then drove to his native Serbia.

A few days later, he left in a hired vehicle, before returning to Belgrade, Serbia, on 5 February. It would take around 26 hours to drive the 2,592 kilometres, or 1,610 miles, from Belgrade to Madrid, the FBI said.

The Peugeot 308 was rented by the suspect on 29 January and, when it was returned on 15 March, the hire company told investigators Mr Knezevich had clocked up 7,677km (roughly 4,000 miles).

The FBI said that security cameras picked up suspicious activity at Ms Knezevich’s apartment building in Madrid during this time, late in the evening on 2 February.

Those same cameras showed a man wearing a helmet entering the building at around 9.27pm, before heading downstairs and using a can of spray paint to cover a security camera.

The lens was not completely obscured and he was seen fastening a piece of duct tape to the entrance door lock, to keep it open.

“Notably, the male, who looks directly at the camera, has physical characteristics that resemble those of Knezevich,” the documents said.

That man was seen leaving the building around an hour later with what “appears to be a suitcase”.

Around the time Ms Knezevich vanished, a local in Spain reported their licence plates had been stolen.

These were later seen on the street where Ms Knezevich’s apartment was. They were also spotted at toll booths in the middle of the night on 2 February into 3 February on a vehicle matching the description of the Peugeot Mr Knezevich had hired.

Impersonations of Ana Knezevich

Then just over a month after Ms Knezevich vanished, an insurance provider got a call from someone claiming to be her, asking for three insurance policies related to the couple’s IT support business in Fort Lauderdale to be cancelled.

“During the call, children could be heard in the background speaking to the Caller,” the documents said. “The Victim does not have any children.”

The phone number used to make the call was registered to Mr Knezevich, the FBI said, and is linked to the business.

One of his employees then told investigators that around 24 April, the suspect asked them to impersonate his missing wife to open a new bank account, even providing the employee with her social security number.

The employee told Mr Knezevich that they felt uncomfortable doing this, as Ms Knezevich was missing still, with the suspect replying that this was “not serious” and that he could not call as he sounded “like a guy”.

The FBI said that all of this had led them to believe that Mr Knezevich kidnapped Ana Knezevich and they arrested him at Miami International Airport as he returned to the US on Saturday.

Mr Knezevich’s attorney Ken Padowitz told The Associated Press that his client had been doing everything he could to help find his estranged wife and that he had no role in her disappearance.

He is being held pending a bail hearing on Friday 10 May, with an arraignment hearing set for 20 May.