It differs in my country, and it is very likely. The US follows an anglo approach to law. No country in the EU follows that – I do understand that it is the easiest to assume that other countries work like you expect, though not very productive.

There is no such thing as a “US Federal DA”.

I assume you mean a US Attorney. OTOH, US Attorneys and Federal Public Defenders (in the judicial districts that have them, its a district by district decision under the governing law) may not be the most knowledgeablr about this since most cases are tried in state court and the federal indigent defense delivery system is very different from most state systems, both in structural model and caseload.