I just tried to file back taxes and someone claimed my child. How can I find out if they been claiming my children for years prior to 2017 not just till now?!

I paper filed with all document's. So please if you can answer. I haven't worked from 2014 to 2017 and I believe the same person is claiming my children. I worked 2017 to 2019 and efile got rejected that how I found out. And I know the other person will get fined but can the irs check for all years someone using my children on the taxes? Not just 2017 to 2019?