80040e14 is an Access Syntax Error
http://www.mikesdotnetting.com/Article/76/80040E14-MS-Access-Syntax-Error-messages[
^]
Possibly your use of table and column names being the same (investigation.investigation), which you should avoid really - just confuses things. Try renaming your column to something else.
On a sidenote, it's 2012 - you can download Visual Studio Express, SQL Express, all for free & have some decent development tools! Why are you hurting yourself with VB6 and Access, the most painful of pairings. :)