The only reference to capitalization that I found is from Bennetts, Section 1, in which he states,
"With the Romans, who regularly employed only capitals ..."
Also, from Omliglot (http://www.omniglot.com/writing/latin.htm
"There were no lower case letters, ..."
"The lowercase letters developed from cursive versions of the uppercase letters. "
Hope this helps in some small way.
Deus me ducet, non ratio.
Observito Quam Educatio Melius Est.