The July 31st 1969 Letters/ The Three Part 408- Clothing Question?

First, sorry about the lousy title. I'm horrible with giving Reddit posts titles.

I started looking at the Zodiac case in 2020 and have been on and off with it. I keep going back to the letters. Are the first three letters the only time he mentioned what a victim was wearing (Darlene Ferrin) or am I not seeing something going back to them? And if that is the only instance he mentions what one of his victims was wearing, why only Darlene?

He dehumanizes his victims by saying the boy, the girl, the taxi driver. States matter-of-factly the number of shots he fired, position of how David and Betty Lou were laying, etc. I know the point of the letters was to prove he was the murderer. But wouldn't stating that Darlene was wearing patterned pants actually humanize her?

I know- why anything when it comes to Zodiac? I have been thinking about this the last couple days and I don't know why it's sticking with me.