But you heard of it first from the UK.
http://www.dailymail.co.uk/news/article-1361684/Gun-used-kill-immigration-agent-Jaime-Zapata-traced-to-U-S.html
I am not questioning that the guns traced back to U.S. gun shops at all.
‘Gunwalker’ Deepens: Agent Zapata Killed By Gun From … Texas?In addition to Phoenix and Florida, it appears the U.S. government had gunwalking operations based in Houston and Dallas.