As best I can ascertain this Alexis fellow worked in the same industry for all his working years. That’s plenty of time to accumulate grudges and resentments. Maybe he didn’t get the promotions or pay he felt he earned/deserved.
If in fact this is true, it will come out...
If the suspect is indeed black, watch for possible allegations of racism...I would not be surprised one bit...And it would certainly not be the first time.