You could be charged with filing a false police report or perjury. they could prosecute him anyway. He could be found innocent and beat the crap out of you. If he really did not beat you, stay quiet. If city goes after him based on your statement, let them know you will not testify.
The response given is not intended to create, nor does it create an ongoing duty to respond to questions. The response does not form an attorney-client relationship, nor is it intended to be anything other than the educated opinion of the author. It should not be relied upon as legal advice. The response given is based upon the limited facts provided by the person asking the question. To the extent additional or different facts exist, the response might possibly change.
If he is being prosecuted based on your lie, it is important that you not commit perjury just to avoid prosecution. The punishment for perjury that results in the conviction of an innocent man will be greater than any punishment for filing a false police report. Talk to your husband's lawyer and tell him the truth about what happened. If your testimony is required, you can take the 5th and refuse to testify unless the prosecutor gives you immunity. If the prosecutor gives you immunity, you can tell the truth without fear of being charged with filing a false police report. If the prosecutor does not give you immunity, the false statements you made to the police cannot be introduced into evidence.
Talk to your husband's lawyer.