The culprit will face severe legal consequences.

The subject could face criminal prosecution

"Strafrechtliche Konsequenzen" implies that criminal charges may be preferred against someone. If, however, the subject is already an accused person as in your sentence, the consequences have already taken place and "strafrechtliche Konsequenzen" is out of place. I would then say:

The accused could face a major sentence.

Agree with M-A-Z. "Legal" does not (necessarily) relate to penal law (Strafrecht).

If you already refer to the people involved as "the accused", it follows that they are already involved in legal proceedings, as M-A-Z correctly points out. However, this does not have to relate to criminal proceedings- for example, you might have a civil trial, where certain matters transpire that would also leave the accused facing criminal charges. This is what your example sounds like to me, and I would suggest the above translation.

If the accused are already embroiled in criminal proceedings, then I'd agree with M-A-Z's suggested translation.