“Once is happenstance, twice is coincidence, the third time is enemy action.” - Auric Goldfinger
I believe in coincidence, but not in incredibly unlikely coincidence. The second killing may have inspired the first, or have been unrelated. If I were an investigator, I would lean towards related, but keep an open mind.
No coincidence there. Like I said before, it's all about “the message”.
I would take this as one....to whom ever “they” are sending it to.