I don't see how information from his twitter account will help prove those charges.
You don't have to. In the US's legal system, the standard for what is discoverable extremely loose. It doesn't just have to be data that you know is relevant, it is any data that might have a chance (even a small one) of containing data that might be relevant.
For example, there's some possibility that the user could have tweeted information about their actions and movements during that time period, and there's some possibility that information might help the attorneys build their theory of the case. So the prosecutors (or plaintiffs, or whoever) are allowed to ask for that information.
It's actually one of the reasons why legal costs in the US and UK are so famously high. The wide net brings in a lot more information that needs to be looked at, and paying attorneys $100s per hour to look at it gets expensive very quickly.
You don't have to. In the US's legal system, the standard for what is discoverable extremely loose. It doesn't just have to be data that you know is relevant, it is any data that might have a chance (even a small one) of containing data that might be relevant.
For example, there's some possibility that the user could have tweeted information about their actions and movements during that time period, and there's some possibility that information might help the attorneys build their theory of the case. So the prosecutors (or plaintiffs, or whoever) are allowed to ask for that information.
It's actually one of the reasons why legal costs in the US and UK are so famously high. The wide net brings in a lot more information that needs to be looked at, and paying attorneys $100s per hour to look at it gets expensive very quickly.