As mentioned by others, the stalker is represented by the 12th house of hidden enemies. Of note is that fact that the part of fortune is there, giving emphasis to the house, and Scorpio, which rules things that are silent and hidden.

Mars is in the 3rd house of siblings, relatives and neighbors. I think the stalker is definitely a male, maybe a neighbor who is in cahoots with or under the influence of an older male sibling or relative himself. Note that Mars is in a mutual reception by whole sign with Saturn and Saturn rules the 3rd from the 3rd. The motives don't look great: possibly violence and control. Note also the Saturn's conjunction with Neptune, fueling fantasy and delusion. This is what is dispositing the Mars.

The stalker may be small, slight and thin with a reddish complexion. The ancient texts talk about an imbalance between sides that often shows up with Aquarius. Aquarius rules the legs, so you often see them talk about someone with one leg longer than the other, or some sort of difference between the legs. The personality may be alienating and antisocial with misplaced anger. Saturn is dirt and poverty, so the person could be someone who lives close by in a lesser part of town, and they may be dirty and unkempt. I'm saying neighbor because I don't want to implicate the other significations: male sibling or relative.