I thought he took out the policy. If so, how could she change the beneficiary?
No-one can take out a life insurance policy on a person (except dependent children) without that person’s signature. The insured person *owns* the policy and can change beneficiaries, cancel or void the policy at any time.
Unfortunately, in this case - Kathy changed beneficiary designation from husband to children (rather than other family members), so he has probably been able to access the policy proceeds as guardian of the kids.
According to witnesses he always had money - notice the plane he owns. It wouldn’t be a surprise if he had some shady business enterprises. IIRC - He and 3rd wife owned a bar.