Jimmy James is a lawyer hired to represent Samantha Sams who has been charged with armed robbery of a local convenience store. Samantha has confessed to lawyer Jimmy James that she is guilty of the crime but wants to plead "not guilty" in court. Jimmy James, as her lawyer, enters a not-guilty plea for her and the matter is set for trial. At trial, Jimmy James refuses to let Samantha take the stand and testify because he knows she is guilty and that her testimony will not be the truth. Is lawyer Jimmy James acting ethically in not allow Samantha to take the stand and/or for representing her in the first place when he knows for sure that she is guilty?