The committee is doing the investigation and if/when they have the evidence of criminal conduct they will pass it on to the DOJ
We already know there is criminal conduct because Clark and Eastman have invoked the 5th amendment, that will be interesting when. Invoking the 5th doesn't mean the committee can question him, they can ask question after question and they will have to answer or plead the on a question by question basis.
It gets interesting that ever question asked where they plead the 5th provides a hint as to what the criminal activity, for example if the committee asks " Did you draft a letter to state senators falsely claiming there was election fraud" Pleading the 5th suggests he did.
