I agree Jane would crack quickly under interrogation, but I'm still not sure the other detectives would be interested in Lauren's story about Bobby unless she had some proof. As far as they're concerned justice has been served. Cases classed as solved aren't easily reopened, so I doubt they'd be interested in questioning Jane. They've moved on to their next case.
Lauren's best bet would have been to try and convince Marcus. He has the power to take it further and to find evidence that could be used for an appeal.