But it may be the only defense, however partial it may be, that Kaczynski's attorneys have. FBI agents uncovered a trove of evidence in his Montana cabin, including virtual signed confessions and a signature completed bomb.
1 Whenever the Moon, Earth and Sun are aligned, the gravitational pull of the sun adds to that of the moon causing maximum tides.  Spring tides happen when the sun and moon are on the same side of the earth (New Moon) or when the sun and moon are on opposite sides of the earth (Full Moon).
Because the tides are influenced by both the Moon and the Sun, it's easy to see that when the Sun lines up with the Moon and the Earth, as during a New Moon or Full Moon (a configuration also called syzygy), the tidal effect is increased.