The arrest of Florence Cassez took place on thursday, December 8 2005 on the Mexico City-Cuernavaca Highway, as she was riding with her former boyfriend, Israël Vallarta. She was detained a whole night, then moved to Vallarta's house in the early morning hours of Friday, December 9 2005. The Mexican Federal Police, which had tipped several journalists, staged an fake arrest on which TV crews of mexican networks Televisa and TV Azteca reported live. Three kidnapped victims were freed and four persons -including Florence Cassez- arrested. Florence Cassez was then presented as a member of kidnap gang "Los Zodiacos", a fact that she has always denied. Vallarta, who was the leader of the kidnapping band, also stated that Cassez had nothing to do with his kidnapping activity.

A few weeks later, during a live TV show, Florence Cassez called and confronted the head of Mexican Federal Police, Genaro Garcia Luna, with the truth about the staged arrest. In the following weeks, Cabeza de Vaca, the Attorney General of Mexico, was forced to admit that the arrest seen on TV was staged. He also tried to shift the blame on journalists, claiming they had requested it. As a result, one journalist was fired by his TV network. Considering he had been defamed in his professional honor, this journalist, Pablo Reinah, filed a lawsuit. In march 2007, The Mexican justice ruled that Reinah had no knowledge that the arrest of Florence Cassez and Israël Vallarta was staged.

Since august 2006, an official probe has been launched by the mexican police against federal agents who arrested Florence Cassez.

Cristina Rios Valladares, and her 11 year old son Cristian Hilario were two hostages freed during the staged arrest. In an initial statement to the police, neither Cristina Rios Valladares nor her son could identify Florence Cassez when she was showed to them. In february 2006, Cristina Rios Valladares changed her testimony and began to claim she could now identify Florence Cassez as one of her kidnappers. Documents show that, in the days following the confrontation between Florence Cassez and Genaro Garcia Luna on TV, Cristina Rios Valladares had spent the day in the Mexican Federal Police's building. Supporters of Florence Cassez also found suspicious that she suddenly remembered that she had been raped by Israêl Vallarta while Florence Cassez insulted her, a fact she did not mention in her first statement to the police.

Ezekiel Elizalde was the third hostage freed during the staged arrest. He has always accused Florence Cassez of being one of his kidnappers. he claimed that she had threatened to cut off his finger and had used a needle to anesthetized it. As proof, he showed the needle mark to the investigators and to the mexican media. After an examination, it turned out that the "needle mark" was in fact a simple birth mark. Elizalde, who claimed that he could remember precisely every single day of his detention cannot,however, remember on which day he was freed.

On 9 March 2009, during Nicolas Sarkozy's visit to Mexico, he requested that Cassez be transferred to a French prison, something she may be entitled to under the 1983 Strasbourg Convention on the Transfer of Sentenced Persons, signed by both France and Mexico. Felipe Calderón agreed to setting up a binational committee to settle this matter. However, given that she has been sentenced to 61 years and that 20 years is the maximum prison term permitted in France, Mexico finally decided in June 2009 that Cassez would remain in Mexico to serve her full term[citation needed].

In may 2009, some mexican TV networks aired a video provided by the Mexican Federal Police. It showed a statement by David Orozco, a man presented as a member of the "Los Zodiacos" kidnapping gang. The man identified Florence Cassez as one of the leaders of Los Zodiacos. However, in june 2010, a court document, signed by judge Eduardo Javier Saenz Hernandez, surfaced. It showed that David Orozco had later denied what he had said on the video. He explained that he had been coerced into doing the video statement by masked policemen who had tortured him with electric shocks and who had threatened to kidnap his wife and his son.