Legal after-calculus
The general rule is that (using terminology from U.S. civil litigation rules) when a "transaction or occurence" is something which becomes the subject of multiple civil lawsuits and those court actions are filed by various categories of parties (groups, individuals, companies) who claim they were harmed, then where there are potential criminal charges to be brought by prosecutors, the larger the number of civil lawsuits, the higher probability the charges will be evaluated as proper and will be initiated. Especially when the prosecutors are federal government authorities rather than at the state level. (I'm omitting any factor of election-year and/or Congressional or legislative political factors, beyond this parenthetical.)
But the sad and tragic saga of Boeing's excursion off of sound engineering and corporate accountability standards is so unprecedented, that any forecast is really just a seat-of-the-pants piece of guesswork.
The roster of lawsuits in Chicago continues to grow.....flight attendants also have filed claims in federal district court against the once-proud airframer.