The Constitution creates a presumption of innocence and requires that the prosecution prove their case beyond a reasonable doubt in any criminal case. Entering a plea of “guilty” at the arraignment erases the presumption of innocence and relieves the prosecution of the burden of proof.
In almost every case, it will make sense to enter a plea of “not guilty” at the arraignment stage of the case, even if you plan to eventually resolve the case. Your attorney can help you decide what strategy is most likely to achieve the results you need.