Helped one move-accused of theft by another.

A year or so ago, my father-in-law and I traveled from our home in Kentucky to assist his estranged wife in moving from Texas back to Kentucky. We moved her possessions from the apartment she shared with her boyfriend/business partner, as well as several items from the store she helped run with her boyfriend. To our knowledge, all the belongings were hers to take, pursuant to her verbal assertions of prior agreements or undisputed ownership. The boyfriend/business partner was not present at any time while we were there, and has never met or spoken to either of us.

Today, my father-in-law received a certified letter from the boyfriend accusing us of felony theft. He claims that no agreement had been made for the items taken from the store, and he is demanding $3000.00 in payment (which he says is considerably less than the items' retail value).

Though I have a J.D., I've never practiced criminal law and currently don't practice at all. After quite a few years, my grasp of things has started to slip a little, so I'd appreciate any help you can provide. Do we have criminal liability? Should I contact a defense lawyer in Texas for representation? If no to criminal liability, could he successfully sue us in civil court?

Thanks for any help.