On January 24, 2009, Marta del Castillo Casanueva (born July 19, 1991), a Spanish high school student, disappeared and was presumably murdered in Seville, Andalusia.

[5] Del Castillo's friends subsequently searched the Seville apartment Carcaño had previously occupied with his older half-brother, Francisco Javier Delgado Moreno, where they noticed a strong smell of bleach and ammonia.

Among other things, he claimed that the vehicle used to move the body was his own moped, but tests showed that it was not stable enough to transport three people in that area, even without accounting for one of them being dead.

[6][8] Specialist Groups, and the Military Emergencies Unit, searched the Guadalquivir between Camas and the estuary at Sanlúcar de Barrameda, using twenty-two vessels, three jet skis, two helicopters, thirteen scent hounds, sonar and specialized underwater body retrieval technology lent by the Dutch police.

Police worked with the hypothesis that the large volume of the Guadalquivir in January and the three weeks between the murder and Carcaño's confession had been enough to either wash the body out to sea before the search began or to entomb it in the bottom mud, which can be two meters thick in some areas.

"[9] On March 18, during the customary reconstruction of the crime at the Seville apartment, Carcaño surprised police when he requested to recant his previous testimony and make a new one.

[7] Also critical was Del Castillo's father, Antonio, who accused the suspects of being deliberately misleading about the body's location because they were hiding additional crimes against his daughter.

[10] Because of Carcaño's new statement, the search team was alerted and directed from the river to the Montemarta-Cónica landfill near Alcalá de Guadaíra, where the trash generated in the city of Seville is processed.

[7] On March 19, confronted with the "unbelievability" of the crime reconstruction at the Seville apartment, Carcaño requested to recant and make yet another statement before the examining magistrate.

According to this account, the two males attempted to have sex with Del Castillo; when she resisted, both men beat her and took her to the bedroom, where Carcaño and García took turns raping her.

The body was disguised with two trash bags, moved out of the apartment on a wheelchair previously used by Carcaño's deceased mother and thrown in the dumpster while García disposed of the knife on a sewer.

García, being under eighteen years of age, was placed in a juvenile detention center for the maximum legal time (nine months) and moved to a supervised home afterward.

[13] In December, it was discovered that a Renault 19 and a Ford Escort, both abandoned since August with flat tires and no license plates, had also belonged to García's mother and her boyfriend, contradicting their claims that they only owned the Volkswagen.

She also testified that Carcaño had not been at her home on the night of the crime, as he had claimed, but that he had left his cellphone there, explaining why tracking data placed him in Camas when the disappearance occurred.

When questioned about a threatening call that she had received during the investigation, P. G. denied that she had identified Delgado as the caller, stating that she had merely picked his voice among several anonymous recordings played to her by police.

[18] On February 1, 2011, Carcaño testified before the court, stating this time that Del Castillo wasn't raped, he killed her alone with the ashtray and stayed in the apartment to clean up the crime scene while Benítez and García disposed of the body in the Guadalquivir.

He claimed to not know where Del Castillo's body was and that his original confessions were falsely made after police threatened to implicate his mother and other relatives.

The early witness statement by P. G.'s grandmother, who had died before the trial started, was read again; it stated that she had washed Carcaño's clothes in the morning and found nothing strange on them.

Her testimony was polemic because she had repeatedly requested to delay or cancel her court appearance claiming illness, yet she had been interviewed the week before on Telecinco's prime-time talk show La Noria, which the network paid money for.

[26] In response, Telecinco was subjected to a viewer boycott and all of its sponsors pulled out of the show, leading to the relegation of the programme to an early morning timeslot before its eventual cancelation.

[27] On January 16, 2012, Carcaño was sentenced to twenty years in prison and to compensate Del Castillo's parents and sisters with 340,000 euro for the murder; he was acquitted of every other charge.

García stood charges for rape, murder and a crime against moral integrity due to his prevention of Del Castillo's receiving a funeral; he argued his innocence and claimed to not know the location of the body, blaming his four previous confessions on police pressures.

The prosecution requested six years of internment in a juvenile detention center, three under supervised freedom and a 616,319 euro fine, the cost of the unsuccessful search for Del Castillo's body.

[16] On March 24, 2011, García was found guilty of the charge of concealment and was sentenced to three years in a juvenile detention center and one month of supervised freedom.

[30] Citing contradictions and "illogical" assumptions on the original ruling, the prosecution requested that Carcaño's sentence be overturned by the Supreme Court of Spain and a new trial take place.

The prosecution considered the story unbelievable and journalists noted obvious parallels with the killing of Lasa and Zabala by the paramilitary group Grupos Antiterroristas de Liberación in 1983.

In 2014, search operations were made in an illegal dumpsite located near the road used by Carcaño to move between Seville and Camas, not far from the river shore where he claimed to have thrown Del Castillo's body in his first confession.

[35] Carcaño reiterated his latest confession before the court, insisting that Del Castillo's body was in La Majaloba, not the dump, and saying that he didn't understand why police were searching there.

[36] In 2015, Del Castillo's father offered Carcaño 18,000 euro if he pinpointed the exact location of the body, with the promise that he would not seek additional charges against him and that he could spend the money in Seville or wherever he wished after his incarceration.

"[37] On September 7, 2015, Antena 3's Espejo Público interviewed a man with the pseudonym "Óscar" who claimed to be a police consultant who had infiltrated García's social circle for the past two and a half years and had recorded 600 hours of conversations on tape.