I had never heard of this case until I listened to a podcast from Thinking Sideways about Mary Anderson. I didn't read every message in this thread but I saw some questions that were answered in the podcast (which is worth a listen if you like true crime podcasts). There's also a very in depth article online interviewing the coroner, who has tried very hard to ID Mary.
1 - The medical examiner did try to track down the IUD by serial number. However due to age of the device, most of the numbers were worn off, and he was unsuccessful searching for the partial number.
2 - Her hands were carefully examined to try to determine her occupation (calluses, marks, etc.) but was also unsuccessful. It also makes no mention of ring marks, which I'm sure would have been seen.
3 - He thinks Mary was educated and possibly worked in a science-related or technology field, primarily because she knew about cyanide and was able to get access to it before the internet.
4 - The medical examiner was able to tell Mary never gave birth to children, so her claims of no family (at least close relations) may have been true.
5 - Mary looks older than the estimated 33-45 years, but this was determined by taking a cross section of her ribs and is thought to be accurate.
6 - Mary's breast surgery was a breast reduction/breast lift. This can be a medically necessary or cosmetic procedure. Insurance would pay for a medical necessity.
7 - Mary was not wearing a Velour track suit. She was wearing a black top and black leggings (pictures are online). Reports said she had 6 Velour track suits hanging in the closet, in various colors.
And the rest is my personal opinion:
- Velour suits were very common in the 1990's, especially for middle-aged and heavier women. They were produced in a variety of materials, quality and price points, from Walmart to high-end department stores.
- Many people seem to think Mary was wealthy or rich because she had expensive items with her (Estee Lauder cosmetics, nice clothes, leather handbag, etc.) I think it's impossible to judge her socioeconomic status by a few items. Some rich people dress in casual clothes, and some people on welfare only wear designer clothes. Personally, taking all evidence into consideration, I would guess Mary is comfortably middle class, but not rich. Her surgery could have been covered by insurance as well.
- I've also read questions about her age and the IUD. IUDs can last around ten years, and while I agree Mary looks older, the medical examiner seemed confident of her age range of 33-45. Although womens fertility enters decline in the 40s, it is still very possible to get pregnant.
