You need to contact an experienced criminal defense attorney in your area ASAP. Either go back to his original lawyer or get a new one to review the file and the new evidence. There are strict time limits to attack a judgment or file an appeal. Time is not your friend. ACT NOW!
I am trying to give you a general answer to your question. We do not have an attorney-client relationship by this response on the avvo website. I have not been retained to represent you. I am licensed to practice law in Kentucky and in federal court in this state and the Southern District of Indiana. You need to seek legal advice from an attorney licensed to practice in your area..
The short answer is that it is very difficult to withdraw a guilty plea after judgment has been entered. CrR 7.8 would likely govern any future motion to withdraw a guilty plea based on "newly discovered evidence" or "any other reason justifying relief" and could, in theory, be filed a the trial court level. The timelines for moving to seek relief from a judgement based on new evidence is 1 year. The timeline for seeking relief from judgment based on "any other reason justifying relief" is "within a reasonable time." You should be able to consult with a local attorney to discuss this in more detail, and to see what your options may be. Although it is unlikely, if your husband does end up successfully withdrawing his plea, the State can still go forward on the initial charges and pursue the initial anticipated sentence of life without parole. Please feel free to call or email if you would like to chat further about this.
Jeff Holmes - Attorney at Law - firstname.lastname@example.org - 360.975.9288. Disclaimer: This answer does not constitute legal advice. This information is based on general principles of law, as well as my general experience that may or may not relate to your specific situation. This information is not meant to take the place of actually consulting an Attorney in your jurisdiction. If you would like legal advice, I would recommend consulting an attorney in your locale.
I hate to say this, but don't expect to accomplish much with that kind of recantation. Courts see allegations like that all the time, are very suspicious of them, and are inclined to regard them as presumptive fabrications. Your husband is going to have to do better than that.
The three answers already given are great advice.
1) Did your husband admit factually to acts constituting the crime at the time of his plea? As opposed to an "Alford" plea where the Defendant says he does not agree to the facts, but wants the deal to avoid the greater penalty. If he admitted to facts constituting guilt, there is a very low likelihood the change in story by the codefendant will sway anyone into believing there has been an injustice.
2) Can he "file an appeal?" He can if it is within 30 days of the sentence, but it will do him no good on this issue, because an "appeal" strictly speaking, is only on the record made in court, this issue would not have been before the Court at the time of sentencing.
3) Can he "withdraw his plea"? He can move to do so, the judge decides if there are grounds to order it withdrawn. There is a huge difference between going to trial, denying guilt, getting convicted, and then discovering a witness is changing their story, and the situation here, pleading guilty, then expecting the plea to be set aside.
4) As indicated in another answer, the outside time limit is a year, but it also must always be within a reasonable time as well of discovering the "new evidence" to warrant any credibility. If possible, it should be made within 10 days of the sentence to ask for arrest of the judgment as well as merely a withdrawal of plea.