We seem to be swinging back and forth between the idea that the motive for ultra privileged spoiled brats with lots of disposable cash take breaks from irresponsible partying to kill people for the thrill of it and then steal their stuff. The contrary idea is that the principal accused here may actually be poor as a church mouse and angry at losing his ultra privileged spoiled lifestyle. So driven by delusional fantasies that convince him some particular person has caused his misfortune, he kills that person and steals his stuff.
Lots of problems with either motivational set, IMO in these sudden deaths. Chief among these would be the fact that these three murders have three entirely different types of victims. Serial killers repeatedly choose the same kind of victim and carry out the murders in almost exactly the same way. In the two cases where we know the cause of death, those causes appear to be different from each other.
In the case of DM, while a limited personal benefit might be said to have been claimed by his son, that inheritance was apparently heavily debt ridden and linked to a business whose potential for profits were high risk prone and at some distant time in the future. Meanwhile, DM had already amassed a considerable wealth on his own, in the form of real estate holdings, etc., so there doesn't appear to be the same potential for an Agatha Christie ending with the scallawag sole heir as the guilty party. Moreover, by all accounts, these men were not estranged from each other but actually quite closely bonded with a lot of shared history between them, nor were their warring heirs in the picture.
In the case of DM, it's rather difficult to see how either the thrill kill meme or the rage transferral notion holds water. According to research I've read, thrill kills are almost exclusively power displays. Sometimes a weapon is used. More often it is not. Abuse and torture are often part of the game. It appeared that TB was a strong and able bodied young man, at least the equal of his murderers. He was not a frail young woman, a homeless man or a little child (the latter as in the Leopold and Loeb case and far too many more.) Statistically, those are the targets of thrill killers.
The opposite consideration, the tormented rage idea, doesn't stand up either. For this idea to be entertained we have to accept that DM was extremely angry about either not having enough money to buy a used Dodge or was somehow otherwise prevented from acquiring one through normal channels. Then he found the names of other people online who he considered to be undeserving of owning such a truck and his anger turned to blind rage. We're told TB's name was an arbitrary connection pulled from an online ad and thus involved total strangers with no prior connection whatsoever. So powerful are DMs emotions that two or more people in his company are also sufficiently and jointly fired up with his rage at a total stranger, that within a half hour or so of meeting him, they join together in murdering him and stealing the coveted truck for DM.
Insofar as the death of LB is concerned, there is also no link to either approach. While she has been referred to as DM's girlfriend, she appeared to have several active relationships, including one with a live-in partner who, she reported to the police, had physically abused her only weeks before her disappearance. While she, reportedly, fit the profile for being in a weak and fragile state of mind, and may have been pestering DM with phone calls, especially given that reportedly he was unusually financially generous with friends, but all those 1 minute calls seem to suggest he wasn't even answering his phone much less seducing her into some clandestine meeting where he and his buddy MS could share the experience of a thrill kill. He, apparently, has had lots of girlfriends. who apparently have all survived his attentions. Nor do I think it probable that he channeled some kind of maniacal rage and self-hate in her direction. Putting a stop to pestering phone calls, however desperate they may have been, from an old acquaintance, just don't measure up to being a cause for hate motivated murder, imo.
TB, WM and (allegedly) LB. Three completely different sorts of people. Three completely different sudden deaths. No clear benefit arising to the accused from any of the murders. IMO.
All IMHO, of course, and with the proviso that, of course, there are many strange things under the sun. Will the missing pieces fall into place at trial? I sure hope so. MOO.