‘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.
The Dog That Hasn't Barked -- Yet. The Texas Connection to the Gunwalker Scandal. - Sipsey Street Irregulars
FWIW I am finding these by mining Nachum's List. I spent more than an hour making specific searches on a search engine and got less than I'm finding there.