Were any of the checks out of the ordinary? Did the account holder NOT benefit from the paying of the checks (electricity, water, gas, etc.)? Is he actually claiming that she "stole" his checks and wrote them or did this come up casually? If he's ranting, it sounds more like a domestic dispute than anything and I'd probably take that stand, depending on the specifics.
If, however, he didn't benefit from the checks being paid and she did steal his checks AND he is willing to press charges, sure.
From your initial post, I'd guess that there is no real issue and that the checks were normal business.