This ^
I found these interesting articles which may have had something to do with the shooting.
From 2018: https://www.cbssports.com/mlb/news/david-ortiz-denies-any-link-to-gambling-on-baseball-after-allegations-in-new-book/
From Jan 22, 2019: https://www.masslive.com/news/2019/01/red-sox-icon-david-ortiz-inks-deal-with-foxwoods.html
Sounds to me like perhaps he had gambling debts