“He was whacked,” said P.I. PJ Tango,
“In a nightclub due east of Durango.
“The Andean mob
“Was the one did the job,
“And the weapon: a snub-nosed charango.”

A charango is a musical instrument from the Bolivian Andes, shaped like a small guitar, and traditionally made using an armadillo shell for the body.

Based on the suggestion: “PJ Tango”