I don't think that in the US, Blacks are generally known for their interest in deer hunting.
If anyone is old enough to remember, the ambush technique reminds me of the Black Liberation Army (BLA), which was suspected of involvement in over 70 incidents between 1970 and 1976 including the murders of as many as 13 police officers. I don't think that any single one of their attacks was as bad as this one.
Almost every cowboy movie I saw growing up where the bad guy wants to kill the sheriff.