On January 24, 2009, 17-year-old Marta del Castillo Casanueva (born July 19, 1991), a Spanish high school student went missing after leaving her home in Seville, Andalusia. Her disappearance led to an extensive search and garnered national publicity surrounding her case. The prime suspect, Del Castillo's ex-boyfriend Miguel Carcaño Delgado, has made different statements over the years about his involvement in her murder and the location of her body. Despite numerous searches, Del Castillo's remains were never found.
Five people were arrested in connection with the disappearance, but only two were convicted. In 2011, Carcaño was convicted for the murder of Del Castillo and sentenced to 21 years in prison.
Disappearance On January 24, 2009, Marta del Castillo was engaged in an online chat with a friend, Silvia Fernández, through Microsoft Messenger. Del Castillo left the conversation with the line ("Fatty, I leave you because [e]l Migue is downstairs and I'm going to talk to him. I'll call you later and tell you about it. Love you."). "El Migue" was the nickname of 19-year-old Miguel Carcaño Delgado, a boy she had been casually seeing for approximately one month. Around 17:00, Del Castillo told her family that she would spend the evening with friends and left her home on Argantonio Street in Seville.
When Del Castillo failed to return home, her family called her cellphone, but she didn't respond. They then contacted her friends, including eventual suspects in her disappearance, including Carcaño and Samuel Benítez. Carcaño admitted that he had seen Del Castillo that evening but claimed that he had left her near the entrance of her apartment block around 21:30. Del Castillo's mother was suspicious and told Carcaño that she'd "throw the police over" him if something had happened to her daughter.
Carcaño attracted further suspicions from the family when he suddenly moved to nearby Camas instead of joining the search effort. There he resided with a new girlfriend, 14-year-old Rocío P. G., and her family. 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.
Investigation The case was investigated by the Underage People Task Force () of the Spanish National Police (CNP). After Carcaño's confession, it was joined by the Homicide Task Force (). Carcaño initially denied any role in Del Castillo's disappearance under repeated interrogations. However, P. G. claimed to have seen blood on Carcaño's pants, and blood found in the lining of Carcaño's jacket was matched to Del Castillo. A luminol test at Carcaño's former apartment also revealed a large bloodstain on the bedroom floor.
Carcaño's first version of the murder Upon hearing of his P. G.'s testimony and of the existence of forensic evidence, Carcaño collapsed and confessed to the murder on February 14. According to this first testimony, Carcaño murdered Del Castillo during an argument on the night of January 24 over his relationship with P. G. The murder weapon was a heavy ashtray which was never found, but which Carcaño claimed to have used to hit Del Castillo on the left side of the parietal bone, killing her. He also claimed to have called a friend, Samuel Benítez Pérez, from a payphone outside his apartment, requesting his help moving the body to Camas. Once there, Carcaño and Benítez threw the body in the Guadalquivir River near a point called Charco de la Pava. Despite this admission, police suspected that Carcaño was not telling the whole truth. 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.
Arrests On February 16, Spanish Minister of the Interior Alfredo Pérez-Rubalcaba announced that Carcaño and Benítez were both arrested under charges of homicide and illegal detention. Also arrested were Carcaño's half-brother Delgado and a 15-year old friend of Carcaño and Benítez, later identified as Francisco Javier García Marín.
Guadalquivir River search
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. A Gelves dock engineer also designed, built and volunteered a rake-like tool capable of removing mud from the bottom of the river.
Three separate tests with pig carcasses weighing fifty kilograms were made. The bodies submerged several times, but in all three cases, they ended on the surface and stuck in a particular stretch of riverbank that was only twenty kilometers long. However, no trace of Del Castillo was found. 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. A "bloodstained cloth" found in an irrigation canal near Camas was revealed to be just painted red after testing.
"El Cuco"'s version In his own testimony, which he later recanted, García stated that he arrived in Carcaño's apartment with Benítez, where they found Carcaño wrapping Del Castillo's body in a blanket under the supervision of Delgado. Delgado then threatened García into silence and stayed at the apartment to clean the evidence while the other three disposed of the body. Police believed Delgado planned the strategy to follow after the murder, based on this testimony and phone conversations between Carcaño and Delgado while both were in remand. In one conversation, Delgado told Carcaño to "say nothing, because the police has nothing."
Carcaño's second version 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. In this second statement, Carcaño blamed the murder on García, saying that he had strangled Del Castillo in Delgado's living room while Carcaño was in the bedroom under the influence of "substances." Afterward, he phoned Benítez and they disposed of the body in a dumpster in the cross between León XIII and Jorge de Montemayor streets, near the apartment.
Carcaño claimed that he had felt pressured by detectives to make his first testimony. Following this second testimony, the other three accused were requested to make new statements of their own, and they were confronted with Carcaño and each other to study their reaction. Benítez and García claimed to not be involved at all, and to not have visited the apartment on the day of the crime. García's lawyer called Carcaño's second statement a joke and insisted his client was innocent. 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. Antonio speculated that his daughter had been cremated in an incinerator where P. G.'s father had been employed in previously.
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.
Carcaño's third version 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. This time he said that he had been drinking, smoking and taking drugs with Del Castillo and García in the apartment. 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. Afterwards, they tied her to the bed with insulating tape and the cord from a heart monitor. Carcaño punched her hard enough to make her bleed, and they strangled her together. 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.
Though authorities were not entirely convinced by this version, it explained the finding of the knife in the sewer in front of the apartment, the presence of Del Castillo's blood and DNA of both Carcaño and García in the bedroom, the finding of DNA belonging to both Carcaño and Del Castillo in the wheelchair's handlers and the testimony of a neighbor who had met Carcaño when he returned to the building with the empty wheelchair.
Witnesses to the statement claimed that Carcaño had looked the magistrate in the eye for the first time and appeared to have taken a load off his mind after he was finished. His lawyer refused to continue representing him after this point. When asked about why he had implicated Benítez and said that he had disposed of the body in the Guadalquivir, Carcaño claimed that he had told the police what they wanted to hear. He also denied any involvement from Delgado, who he claimed had left the apartment at 20:30, ten minutes after Carcaño arrived there with Del Castillo. Carcaño also denied having talked about the murder with P. G., in contradiction with her own testimony, which stated that he had told her "everything."
It was estimated that in the time between Del Castillo's disappearance and Carcaño's third confession, around 65,000 tons of trash had arrived at the landfill. As a result, it would be "very difficult" to locate her body. Landfill employees and policemen revised 60,000 tons over the course of thirty-two days unsuccessfully, even though they knew a particular area where the trash was dumped in the days following the murder. They also found no human DNA in the dumpsters that Carcaño had said were used to dispose of the body. Eventually, police concluded that Carcaño had not thrown the body in a dumpster and speculated that he had falsely confessed a rape with the intention of obtaining a bench trial rather than a trial by jury.
Provisional release of Delgado, Benítez and García On May 21, Delgado was released with the condition that he visited the courthouse every Monday. Reasons included the fact that his part in the crime was necessarily small, if any, and that his alibi had been partly confirmed by mobile phone tracking placing him on the road to Carmona at 21:01. Delgado, who had always denied his involvement, offered to take a polygraph test, but the magistrate rejected the idea. After his release, Delgado made a press statement accusing Carcaño of lying to him, and about his involvement in the case. Benítez was released on December 10. He had requested to be released on two previous occasions, but he was denied arguing gravity of the suspected crime and a risk of tampering with evidence after release. 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.
Evidence in vehicles owned by the family of García