A kind member enlightened me as to why it was said that the two girls are known to have died on different days. The obituaries of the girls each show a different date of death. I'm proposing that the families may have chosen different dates, one choosing the date on which the girls went missing and the other choosing the date on which the girls were found.
Liberty "Libby" German 14, of Delphi, went to be with the Lord on February 13, 2017.
http://www.legacy.com/obituaries/jconline/obituary.aspx?page=lifestory&pid=184160551
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Abigail J. "Abby" Williams 13, of Delphi, died Tuesday, Feb. 14, 2017.
http://www.legacy.com/obituaries/jconline/obituary.aspx?page=lifestory&pid=184160552
Autopsies were performed Feb 15th:
"Autopsies have been scheduled for 8 a.m. Wednesday, according to police."
http://fox59.com/2017/02/14/officials-give-update-on-two-missing-carroll-county-teens/
The funeral arrangements were published February 16th:
"Funeral arrangements set for Delphi teens
Posted 6:42 PM, February 16, 2017, by
FOX59 Web, Updated at 03:41PM, February 17, 2017"
http://fox59.com/2017/02/16/funeral-arrangements-set-for-14-year-old-delphi-teen/
Not sure if the autopsy results would have established such a precise TOD so quickly, by sometime the following day when the funeral arrangements were published? Their last SM post was around 2pm on the 13th, and their bodies were discovered a little earlier than that on the 14th, so we know they were killed within that (approximately) 22 hour period. Personally, I can't see the killer killing one girl and leaving the other alive for several more hours, but that is just my opinion. I think it is more likely that each family, during their own private funeral arranging, chose the DOD as either the missing date or the found date. Thoughts?