They haven't been caught red-handed, but their reserve claims are highly suspect[1]. Predictions that Binance is next are pretty credible in my mind, and the DOJ is already looking[2] in that direction.
Also given that the big banks haven't been hit hard from this scandal DOJ might go harder at Binance since they probably didnt want to destabilize the economy unnecessarily with pursuing both at the same time (uncertainty around exposure to crypto in the wider market).
[1] https://mishtalk.com/economics/binances-alleged-crypto-audit...
[2] https://arstechnica.com/tech-policy/2022/12/doj-divided-over...