Emily wrote:

Dave S wrote:

How does detaining them in the course of a criminal investigation
constitute holding them hostage?

Because the Brazilian government has zero reason to suspect criminal
action on their part.

Let's not forget that the 737 crew could have caused the accident, but
not one's even thinking of that option.

First, they are not being detained. The government is holding their
passports so they can't leave the country. The US would probably do the
same if a foreign national was involved in an such a major incident under
suspicious circumstances.

Second, the early analysis of the recorders and ATC logs suggests that
the transponder on the Legacy stopped functioning sometime before the
collision, and started functioning again after the collision. the
investigators want to determine if it was deliberate or a technical
fault.

The Brazilians also claim that the crew on the Legacy "ignored" an ATC
request to change altitude before the collision. They were flying at an
odd altitude (37,000 ft) in a northwest direction, and had been told to
descend to 36,000. While the crew didn't respond to radio calls before
the collision, they got in contact with ATC after the collision.

The judge who ordered the passports held felt there was enough evidence
to warrant holding their passports until an investigation into possible
negligence could be completed.

I haven't seen anything yet to explain why the 737 wouldn't have been
told to change course or altitude by ATC with the Legacy not reponding.
However, the news reports are really vague and incomplete, so I'm not
sure anything reported so far about the collision can be taken as fact.