No lawyer can promise that. Anyone who does is lying to you. But a private lawyer will fight harder to keep you out of jail because they have the time and the resources to do it. They can look for ways to get the charge reduced. They can argue for probation instead of jail. They can find mitigating factors the prosecutor will not look for on their own. A good private lawyer knows every lever to pull. A public defender does too — but does not have the time to pull them.
