Falsely accuse of child abuse my son-n-law was accuse of abusing his nice 25 yr ago by her x mother n law ?

the mother n law works at DHS the nice was in jail for not paying her fines she had her case worker to place her kids in the care of my daughter and her uncle the mother n law wanted her kids so she had someone to call DHS and say my son n law did this all full thing just so she could get the kids so we had three days of hell and now they say my granddaughter can go home they don't have a case on my son n law witch we knew they didn't but it has up set the whole family because of a lie should my son n law get a attorney we don't think this person should work for DHS if she is going to use her power for her own satisfaction