Beneficiaries vs Will

My fiance was killed in an accidental shooting just two months before our wedding. He had made a will that explained how all of his account should be split up and who received what portions. There are beneficiaries on the accounts named in the will that do not match. The beneficiaries were set years ago. It is his ex wife. He had found out about this just weeks before his death and elected to wait until after our wedding to change them. So do you follow the will or the beneficiaries? This is on retirement and investment account.