Family at heart of GM recall case accuses automaker of cover-up

ATLANTA -- Twenty-nine-year-old Brooke Melton died three years ago in a Chevy Cobalt. Investigators determined the ignition switch was in the accessory position.

GM has since recalled millions of cars with a similar ignition switch problem, which causes the car to shut off and vehicle safety systems to stop working.

Brooke Melton CBS News

Melton's family hired a lawyer to sue GM and eventually settled in September of last year. However, when GM issued a recall four months later, they were angry, believing GM did not tell them the truth.

During sworn testimony in the case, GM engineer Ray DeGiorgio was asked whether he knew about any changes to the switch design.

"I am not aware about this change," he testified.

But a document from April 2006, seven years earlier, shows DiGiorgio's signature on a document authorizing an ignition switch change.

"The Meltons settled their case believing GM knew nothing about the ignition switch design change," said Lance Cooper, the Meltons' lawyer. "They now know they were lied to."

Are more deaths linked to GM ignition switch defect?

Cooper's team was the first to independently discover the ignition switches were defective. He says that now, because a GM engineer perjured himself on the stand, the Melton settlement should be rescinded.

Cooper acknowledges refilling the case is a big risk.

"But for the Meltons, there's no financial incentive to do this," he adds. "It's simply to get at the truth."

GM issued this response Monday afternoon: "As an initial matter, General Motors denies the assertion that GM fraudulently concealed relevant and critical facts in connection with the Melton matter. And GM denies it engaged in any improper behavior in that action."

GM says it will not reopen the case; at this point, it's up to a judge.