The archetype of the fool in Spanish entertainment is centuries old, tracing its roots back to the of the 16th century (such as Lazarillo de Tormes ). While the pícaro (rogue) was clever, they were often surrounded by tontos —corrupt or blind authority figures whom the rogue would outsmart.
The word "top" is the key to understanding the entire sentiment. In this construction, it is almost certainly used as a slang adjective meaning "the ultimate," "the peak of," or "the best example of." Therefore, can be interpreted as "a top-tier felony" or "the highest level of a serious crime." el tonto follando con la porrista felony top
In broader entertainment and social media, "el tonto" is frequently used as a trope or common expression: Endearing vs. Insulting The archetype of the fool in Spanish entertainment