All MOO
Criminal defense attorneys are bound by ethical rules that govern their conduct, including rules regarding truthfulness and candor to the court. While defense attorneys have a duty to vigorously advocate for their clients' interests and to present the best possible defense, they are generally not permitted to knowingly make false statements to the court.
A defense attorney can assert that their client is innocent if they genuinely believe that to be the case based on the information available to them. However, if the attorney knows or strongly suspects that their client is guilty, they cannot ethically assert the client's innocence.
If a defense attorney were to knowingly make false statements to the court, such as asserting their client's innocence when they know or strongly suspect otherwise, they could face disciplinary action by the state bar association, which could include sanctions or even revocation of their law license. This is because knowingly making false statements in court would violate the attorney's duty of candor to the tribunal and undermine the integrity of the legal system.
While true that a criminal defense attorney can say their client is innocent, it's a pretty rare occurrence because if it turns out there is solid evidence against the client then the attorney will have lost all credibility going forward & it will also affect their credibility in other cases.
So, while defense attorneys have a duty to zealously advocate for their clients, they must do so within the bounds of ethical rules and cannot knowingly make false statements to the court.
All MOO