There is absolutely no doubt that a sitting President can be indicted.
Sorry, the DOJ under Clinton, with counseling from the USSC, made the policy decision not to allow a sitting President to be indicted.
The DOJ stated that doing so would be the equivalence of 1 single prosecutor assuming the responsibilities and powers - specifically / especially powers of Impeachment - bestowed upon Congress to reverse the decision / choice made by the American people, to -un-do' a democratic election, to 'un-elect a president'.
The USSC argued that it was NEVER their desire nor should it be anyone's desire to allow 1 single person, especially should they be extremely partisan, have the power / authority to 'Impeach' a sitting US President on their own, which they deemed indicting a sitting President would be.
Allowing this to happen would enable / allow to happen exactly what is going on now - a rabidly partisan party / prosecutor to 'Impeach' / 'undo' an election simply because they hate the man / his beliefs / agenda / etc and not for some ACTUAL crime (which Democrats have not proved, after 2 years of investigations and come up with nothing, this President has done - NO CRIME / NO EVIDENCE.)
This DOJ just recently publicly re-affirmed their stance on this.
NOT going to happen, no matter how badly the Democrats / snowflakes want to KEEP ON HELPING THE RUSSIANS divide this nation.