I don't fully understand your requirements, but here's another possible approach to some kind of solution.

Notes:

• The example contains both false positives and false negatives.
• The name 'John Jacob Astor' is split across two lines: there is a further processing step to squish some (but not all) whitespace in extracted names into a single blank.
• An attempt is made to handle hyphenated names.

>perl -wMstrict -le
"my $letter =
   qq{One Mr. John Doe was a very good friend of John Jacob \n}  .
   qq{Astor. They met often with William and Henry James and \n} .
   qq{Capt. Jean-Luc Picard at the quaint Tavern On The Green.};
 print qq{''$letter''};
 my $Capped    = qr{ [[:upper:]] [[:lower:]]+ }xms;
 my $name      = qr{ $Capped (?: - $Capped)*  }xms;
 my $full_name = qr{ $name   (?: \s+ $name)+  }xms;
 my @names =
   map { tr{ \t\n}{ }s;  $_ }
   $letter =~ m{ $full_name }xmsg
   ;
 print qq{'$_'} for @names;
"
''One Mr. John Doe was a very good friend of John Jacob
Astor. They met often with William and Henry James and
Capt. Jean-Luc Picard at the quaint Tavern On The Green.''
'One Mr'
'John Doe'
'John Jacob Astor'
'Henry James'
'Jean-Luc Picard'
'Tavern On The Green'
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.