I have just read Pomeroy's The murder of Regilla. After two millennium it is hardly likely that any conclusion will meet a criminal level of proof and Pomeroy does not give a final verdict. On the other hand Pomeroy does seem to me to have a favourite conclusion. There are two suspects Herodes Atticus, her husband, and Alcimedon. a freedman of Herodes Atticus. As the defence case (in the subsequent trial) was that Herodes Atticus ordered Alcimedon to punish Regilla and over did it, kicking her in the stomach, there are many possible ways to share out the burden of guilt.
Pomeroy seems to load almost all of the guilt onto Alcimedon. This is on the "who gains?" principle. Alcimedon she suggests may have poisoned Herodes mind against his wife and when given a blank check made full use of it. With Regella out of the way he was able to secure his place in Herodes affections.
That Alcimedon was treated well after the murder of Regella is pretty clear but it seems to me doubtful that Alcimedon could have anticipated that outcome. Even if Herodes had become so alienated from his wife that he bore no ill will against whoever killed her I doubt whether Alcimedon would have been so sure that killing Herodes future son might not result in Herodes turning on him.
Herodes was known for his outbursts of anger and may have killed before. Hence a more likely scenario seems to be for Regella's resentment against her domineering husband to have provoke a rage that led Heroides to attack his wife so brutally that she died of her injuries. Then, after the event, loyal Alcimedon offers to carry the can. That seems a far more likely explanation for Herodes very generous treatment of Alcimedon and his family.
Some of you may well know of evidence that Pomeroy had ignored that can be used in Herodes defence. What I find curious however is why Pomeroy favors a solution that is so at odds with the evidence she presents.