He confessed to hundreds of murders. Investigators could only ever confirm a fraction of them — and even that fraction makes him one of the most prolific killers ever caught.
Pedro Alonso López, known as "the Monster of the Andes," is a Colombian serial killer convicted of murdering young girls across Ecuador in the 1970s. He claimed a far higher victim count than was ever formally confirmed, a distinction that's often lost in how his case gets retold.
A Difficult, Abusive Childhood
López has said he was raised by his mother, who worked as a sex worker, and that he was expelled from home at age 8 after being caught in an incident with his sister. According to his own later accounts, he experienced severe abuse as a homeless child and later as a teenager, including sexual abuse he said was carried out by an adult after he'd been taken in by an American family and enrolled in school.
Confirmed Murders
López was arrested in Ecuador in 1980 after a flash flood exposed a mass grave, and he subsequently led police to 53 additional gravesites, all belonging to young girls. Ecuadorian authorities were able to formally confirm and convict him for these murders. He was sentenced to Ecuador's maximum possible term at the time.
Far Higher, Unconfirmed Claims
In prison interviews, most notably one with freelance photojournalist Ron Laytner published widely in 1980, López claimed a total victim count exceeding 300 across Colombia, Peru, and Ecuador. This figure came entirely from his own self-reporting and was never independently confirmed through physical evidence or formal conviction in Colombia or Peru. It's worth being clear about that distinction: the 53 Ecuadorian murders are documented and confirmed; the far larger totals commonly repeated in tabloid coverage rest on the unverified word of a confessed serial killer with every incentive to exaggerate his own notoriety.
A Controversial Release
Due to a combination of Ecuadorian sentencing limits and reported good behavior, López was released from an Ecuadorian prison in 1994, then deported to Colombia, where he was briefly held in a psychiatric facility before being released again in 1998. His whereabouts and status since then have never been definitively confirmed by authorities, and various unverified reports over the years have claimed he was living freely, had died, or had reoffended — none of which have been substantiated with certainty.
Frequently Asked Questions
How many murders was Pedro López actually convicted of?
He was formally convicted and sentenced in Ecuador for 53 murders. His often-cited claim of over 300 victims came only from his own unverified prison interviews.
Is Pedro López still alive?
This has never been definitively confirmed. Various unverified reports have circulated over the years, but his current status remains unclear.
Why was he released from prison?
Ecuadorian law at the time capped sentences at a maximum term regardless of the number of murders, and he was released in 1994 citing good behavior, before being briefly institutionalized and then released again in Colombia in 1998.