Well, there you are --- HKS and Methadone go hand in hand and I'll venture to say that he got her addicted to drugs --- easy to control a drug addict when you're the supllier.
When I watched the interview on E.T. tonight, I really think HKS was crying that Anna didn't last another couple weeks when they were supposed to get married, or as it put it, "make it official". If she had died three weeks from now, he would be the sole executor of her estate, get her money, bury her, and take custody of the baby.