Some technical gymnastics:
The Ascendant in Dahmer's chart rises in Libra at the degree of the Sun's deepest debility. The Sun is most exalted at 19 degrees Aries and is at its maximum fall at 19 Libra. I think this is an immediately important factor since it is a daytime chart (the Sun is above the horizon and so is the luminary of the sect in favor). The ruler of the Ascendant is Venus (the benefic of the sect not in favor - it prefers the night). It has 'power' in its own sign, Taurus, so it is good at getting what it wants, even if this is not particularly good for the native. It is in the 8th whole sign house, so it does not see the Ascendant. The 8th house is the traditional house of death. Venus is also rising before the Sun, and so is a morning star Venus, showing her more assertive and warrior-like face. Venus connects to Rahu, the head of the dragon (north node of the Moon), by a close trine aspect, but it is the sign of Venus' fall (Virgo) in the 12th house. The exaltation ruler (and almuten) of the Ascendant is Saturn in Capricorn (its own sign) in the whole sign 4th, giving a strong connection to and esteem for the parents and tradition. Also think of the 4th as pertaining to things buried, or deep under the earth. Saturn is, however, in a tight square aspect to the Ascendant, so we see potential for stress and blockage here. Houses 4, 7, 8 all pertain to death; in the 4th we return to the place from which we came, 7th is the setting place, and 8th is the experience of death, often not our own but the experience of death and upheaval around us (sometimes called a place of transformation). Also of note here, as all these places are highlighted, houses 4, 8, 12 according to the 13th century astrologer, Guido Bonatti, were thought to be houses of varying kinds of imprisonment.
The Moon, luminary of the night sect (not the sect in favor), is waning and is right on the horizon, setting at the time of his birth. The Moon is configured in the whole sign 7th (traditional house of death = setting Sun) with the contrary to sect malefic, Mars, which is in its own sign Aries (making it strong, though potentially reckless). Moon (pertaining to body, nourishment, feelings, and the irrational) receives a dominating square from both Jupiter - which is debilitated in the sign of its fall, Capricorn, and is also the sign of the Moon's detriment - and Saturn, strong in Capricorn, but seeing the Moon in the sign of its own fall, Aries (which it does not care for). Mars receives these squares as well, and since Capricorn is the sign of Mars' exaltation, it is strengthened further (and apparently not for the better). Remember, strong does not equal good. Saturn sees Mars in this square and being the sign of its fall is not especially pleased. Mars is also the lord of the 7th house of partners and open enemies.
Mars severs, it is related to cutting and knives, it separates . . .
Mars is also antiscia the moon's Node - a point symbolizing connections. Mars|Node can be work connections, physical, sexual, or athletic connections, connecting with men, or collaborative or quarreling connections. Mars can also sever or cut connections (Yikes!- when considered literally). Antiscia, being symmetry around the cardinal axis or Aries Point, is indicative of how we connect to the world. Dahmer connected via Mars|Node. Of course, a general Mars|Node connection means a lot of different things as noted, dependent on varied context and circumstance.
The Sun, the luminary for the day, is configured with Mercury, the lord of 9 and 12 and in the curious, dual sign Gemini. Mercury is a youthful and somewhat androgynous character, one that moves between worlds (the underworld and the earthly world). The primary trigon lord for Air signs in a day chart is Saturn, so both Sun and Mercury are tied strongly to Saturn at the bottom of the chart.
Chart set up from the Lot of Fortune.
(Vettius Valens, a 2nd century astrologer, instructs us to use the Lot of Fortune as an alternate Ascendant.)