Getting Your Hands On The Biography
If you're looking to read about Pablo Escobar and the Medellín Cartel, there are a handful of solid biographies that actually do the job right. The market is flooded with garbage, so you have to separate the useful from the sensational. I've spent years tracking down accurate source material on this subject. Most books get basic facts wrong or lean too hard into glorification. What I found useful is focusing on the detailed ones written by people who actually had access to primary documents or direct interviews. The biography you'll commonly see referenced is marked up by various publishers with titles like that. You're going to want to check the author and publication date. Gary Marx's work and the Bolivarian Foundation's publications tend to have better sourcing than the Hollywood versions. Look for books published before 2010 when possible because newer ones sometimes repeat unverified claims.
Here's the practical problem I ran into constantly: a lot of the downloadable PDF versions floating around are incomplete scans, missing entire chapters on the cartel's financial operations, or they're corrupted files that won't open past page forty. I wasted weeks on this before finding a reliable workaround. My solution was to use Google Scholar and cross-reference the ISBN with library catalogs. The WorldCat database will tell you exactly which libraries hold physical copies. I ended up borrowing from the University of Miami's Latin American collection, which had the complete annotated edition with chapter notes intact. If you need digital, project Gutenberg occasionally has public domain material, but most Escobar biographies are still under copyright so you're stuck with legal channels. For actual purchasing, Amazon carries several editions. The Barnes and Noble site has better filters for academic versus popular titles. I recommend checking Goodreads reviews but ignore the five-star ones unless the reviewer mentions specific sources or archives they consulted. The ones that matter usually have three or four star ratings with detailed commentary about factual accuracy.
A few counter-intuitive things to know that beginners miss: the chronological biographies are generally more reliable than thematic ones. Books organized by topic like "drug trafficking methods" or "violence in Colombia" often reconstruct events based on single sourced accounts without cross verification. The narrative structure forces authors to fill gaps with speculation presented as fact. Another thing nobody tells you: Colombian government archives from the late nineties contain declassified documents that contradict several popular biographies. I found discrepancies in death toll estimates between what Narco magazine published in 1997 and what the Colombian National Archives released in 2003. The published books usually cite the earlier figures because they were written before the archive opening. The main limitation of most Escobar biographies is that they rely heavily on the accounts of former cartel members who were negotiating reduced sentences. Their stories have clear incentives for exaggeration or shifting blame. I learned to verify any claim about daily operations or specific events against multiple independent sources. If only one person describes a meeting or transaction, treat it as potentially unreliable.
Get the Full Details

There's also the problem of Spanish language sources being ignored. Many English language biographies don't consult Colombian journalism from the period, which sometimes has better operational details than the official narratives. El Tiempo and El Espectador archives from 1989 to 1993 contain firsthand reporting that corrects several major errors in the popular English texts. If you're doing serious research on this topic, budget at least three to four months for proper source verification. Reading a single biography will give you a story, not an accurate picture. The detailed financial records and court documents tell a different version than the gangster mythology that dominates the genre.