Born in 1963 in Machala, El Oro Province, Ecuador, Gilberto Chamba led a seemingly ordinary life. He worked as a taxi driver and was married with two daughters. However, beneath this façade, Chamba harbored a dark side that would later earn him the moniker "The Monster of Machala." Between 1988 and 1993, he used his taxi to prey on young, unaccompanied female students, offering them rides before assaulting and murdering them. His crimes went undetected for years until a surviving victim, a sex worker, provided testimony that led to his arrest in 1993. Chamba was convicted of murdering eight women and raping two others, receiving a 16-year prison sentence. Due to good behavior and a general amnesty during the Great Jubilee in 2000, he served only seven years and was released in 2000. Following his release, Chamba legally emigrated to Spain, where he resumed his life, working various jobs and attempting to reintegrate into society.

In Spain, Chamba settled in Lleida, Catalonia, and found employment as a parking attendant at the Illa de l'Oci entertainment complex near the University of Lleida's Law Faculty. On November 23, 2004, 21-year-old law student María Isabel Bascuñana disappeared after informing her parents she wouldn't be home for dinner. Two days later, her body was discovered in the trunk of her car, parked a few streets away from the cinema. She had been brutally raped and strangled, with garbage bags wrapped around her body.

Investigations revealed that Chamba had been harassing María and other female students, often requesting their phone numbers under the pretense of contacting them if issues arose with their vehicles. Many of these women later received sexually harassing calls, which they suspected originated from Chamba. Further evidence linked Chamba to the crime: María's phone had been used to make calls to phone sex services shortly after her disappearance, and garbage bags matching those used by cinema cleaners were found in her car's glove compartment. DNA tests on semen found on María's body matched Chamba's, leading to his arrest on December 1, 2004.

During his trial, Chamba denied the charges, claiming police had fabricated evidence. However, the overwhelming forensic evidence led to his conviction. On November 5, 2006, he was sentenced to 45 years in prison: 20 years for María's murder, 12 for her rape, and 13 for the attempted rape and murder of a Romanian prostitute who testified against him. Chamba is currently incarcerated at Module 6, Centre Penitenciari de Quatre Camins in Catalonia, Spain.​