Leader in the Senate say the plan is a cost-cutting move, but others see it as a power grab.
Cooper, a Democrat, rolled out law enforcement supporters from across the state Monday, including chiefs of police, sheriffs, and district attorneys who literally stood behind him at a news conference.
To back his argument, Cooper pointed to the many political corruption cases handled by the SBI in recent years. The vast majority of the public officials investigated during that time were - like Cooper - Democrats. But they were investigated at a time when Democrats held the governorship.
Cooper said putting the SBI under the Department of Public Safety - with a secretary appointed by the governor - could hinder future corruption investigations of the party in charge.
"The SBI has provided a check on power. And no matter who controls the state legislature, the governor's office or the attorney general's office, this system works best. Putting the SBI under any governor's administration increases the risk that corruption and cover-up occur with impunity," said Cooper.
One of the district attorneys at the news conference - Jim O'Neill, an elected Republican from Winston-Salem - said he didn't see the move as a political power grab - just an attempt to save money. But, he said he still didn't agree with the move.
He believes the SBI should remain under the AG's office and that the legislature should instead better fund the SBI lab to eliminate long delays on evidence analysis.
"Unfortunately, in legislatures past, a lot of the blame has been unfairly placed on the lab and the agents. And that's been misplaced and misguided. And, again, I say that the real problem is that we have not properly funded the lab and we have not properly funded SBI agents over the years," said O'Neill.
But Senate Republicans defended the plan at a news conference Monday to talk about the budget.
"It simply does not make sense for the state's top attorney to supervise the SBI just like it wouldn't make sense for your local district attorney to supervise your sheriff or police," explained Senator Harry Brown (R) Jacksonville.
Currently, Virginia has a similar system to the one proposed by the Senate, while state bureaus of investigation are independent agencies in South Carolina, Georgia, and Tennessee.