There’s a smoke trail

This malaphor was uttered by Mark Teixeira, discussing Robinson Cano’s suspension for violating MLB drug rules:

“Robbie Cano’s assistant was on the list for Biogenesis,” Teixeira said. “Of course he had his assistant buy stuff for him. Alex Rodriguez got popped by Biogenesis and Melky got popped. They’re his best friends. When someone gets lumped into that group, it’s because there’s evidence, there’s a paper trail, there’s a smoke trail. …

https://www.reuters.com/article/us-baseball-mlb-teixeira-cano/ex-yankee-teixeira-not-surprised-at-cano-suspension-idUSKCN1IJ09B

This is a mash up of “paper trail” (written evidence of someone’s activities) and “smoking gun” (indisputably incriminating evidence).  The speaker might also have been thinking about contrails, which are essentially smoke trails from airplanes.  A big thanks to John Costello for spotting this one!