Achacaron comes from the verb achacar, which means "to accuse," "to blame," or "to attribute something negative to someone." It's a less common word than acusar and carries a slightly more informal or colloquial tone.
In the context of "Soy Montero," the lyric "Me achacaron varias veces y las rejas no miré" translates to "They accused me several times and I didn't see the bars (of jail)." This line highlights the protagonist's brushes with the law and his ability to avoid imprisonment, making achacaron a key word in understanding his narrative within the cartel world.
"Soy Montero" opens by naming itself — "Soy Montero se titula el tema de los corridos 2018" [I'm Montero is the title of the 2018 corrido song] — before the narrator lays out how he got here: dealing at fifteen, "Vendía gallitos pal estrés" [I sold joints for the stress], then moving up to "Polvo blanco fui sacando" [I was moving white powder]. Six years later he counts himself made: "Seis años de experiencia y ya estoy en el cartel" [Six years of experience and I'm already in the cartel].
The hook turns his own last name into proof he made it out the two ways that story usually ends. "No estoy donde yo quiero, ni enterado en el suelo" [I'm not where I want, nor buried in the ground] sets up the title line itself: "Fue rayado en mi cuerpo, mi apellido por cierto" [It was inked on my body, my last name, by the way] — a tattoo standing in for a life that could have gone the other way.