An expert says it may be hard, but not impossible, to prove genocide in Ukraine

Should the atrocities in Ukraine be called war crimes, ethnic cleansing or genocide?

The terms can be difficult to differentiate, but experts say the separate labels are crucial when investigating perpetrators and seeking justice in international courts.

"We are definitely seeing evidence of crimes against humanity and war crimes," says Leila Sadat, an expert on war crimes and international law at Washington University in St. Louis.

"Genocide requires this special