Marital finances/credit history question.

In the credit report of a married couple in the U.S., does all recent activity for both people show up (even from before they were married)?

For example: John has debt A and debt B. Debt A is written off as bad, then John marries Jane, then Debt B is written off as bad. Do BOTH bad debts, A and B, now show up as points against them on both of their credit reports? Or does only debt B show up on both their reports?