I suspect the primary reason is they are inordinately concerned about their own reputation among their followers.
If there is irrefutable evidence that JWs are just like any other religious organization, with their fair share of pedophiles, murderers, thieves, drunkards, etc., then why should a JW continue to belong to them and, perhaps just as importantly, continue to contribute to the organization?
JWs as an organization are far less fun and interesting and fulfilling than Catholics & Baptists and Methodists & Lutherans & you name it.
The one thing they've apparently got is "hey, we're more spitirually pure than everyone else out there."
Take that away, and why would anyone stick around?
Thus, in order to maintain the illusion, there is almost always a near-maniacal effort to cover over anything that sullies the organization's reputation.
I expect, sometime this week, a sanctimonious press release from the WT PR department condemning the actions of "former member" Holt for the murder of Whitney Heichel. It will talk about how "we view life as precious, just as Jehovah does" and "we abhor murder" and "the actions of a former member in no way reflect the condition of those in the congregations."
By the way, Holt will be a "former member" as soon as the CO and 2 top-dog local elders get together to pronounce him guilty and DF'ed, if such a meeting has not already happened. The "judicial committee" will take no longer than 5 minutes.