Jeeze HN, why the downvotes? I give you Article VIII of the Outer Space Treaty of 1967:
> A State Party to the Treaty on whose registry an object launched into outer space is carried shall retain jurisdiction and control over such object, and over any personnel thereof, while in outer space or on a celestial body.
The American module group, where this alleged crime probably took place (as US astronauts use the laptops in their own area), is governed under the USA's laws.
But the nexus of the crime involves a US person, so the US has the authority to investigate independent of what or where or who allegedly was involved.