You’re already jumping to conclusions, specifically that he was definitely in the cell with his wife when she died and that she was killed.

There’s still some doubts that can be cast, especially given the few details we have.

He didn’t have control over who could enter or leave the cell, it’s possible someone else did the murdering.

Heck with the evidence we have access to, it’s possible she never entered the cell alive.

It could have been accidental as the result of something consensual.

It could be coincidental that something consensual happened and after which see died of an unrelated cause.

It could have been suicide, where she wanted to be with him at the time.

Walz and AOC did a stream together during campaign season, so there’s probably a good chance they’re staying in relatively close communication.