I'm not a student of serial killers but it's hard for me to even begin to formulate a motive for this particular guy. Men that kill women is common; women that

I'm not a student of serial killers but it's hard for me to even begin to formulate a motive for this particular guy. Men that kill women is common; women that poison men is pretty common. Let's theorize these people have a fetish for killing. Another category is those with automatic weapons that kill groups of people all at once. Just for notoriety knowing they will be caught or expect to commit suicide at some point in the process. But Zodiac is killing couples he doesn't know at a distance with a gun (or a knife, likely because a gunshot would draw too much attention). He wants to be notorious but not personally notorious? He just has a hate on for anonymous couples? Are there (m)any more examples of this kind of killer? Hypothetically, if he could kill say a hundred couples from a distance with a bomb would that motivate him? I'm just not getting it.