Maybe. There are objected oriented APIs for building database interfaces.
What the government needs to do is develop an extension of one of those API sets for government use. That shouldn't take more than $7-10 million dollars and 10-18 months to develop, and simultaneously develop several government applications, including the FBI application. And any new development after that would cost significantly less, and time to deployment would be minimized.
Open source CMS solutions are great examples of how the modular approach and common, object oriented API can allow the creation of unique websites from a common code base.
Its also obvious that the FBI did not look and see what other government/military agencies are using. The FBI is not the only agency that needs to be secure.
I'm sure they are of the mindset that they need a "different" software when one might already be made and just needs to be modified.