Complex sentence: He was a member of the Arajs Kommando which was involved in the mass murder of Latvian Jews as part of the Holocaust but he never stood trial, though there are eyewitness accounts linking Cukurs to war crimes.
Split into simpler sentences: He was a member of the Arajs Kommando, which was involved in the mass murder of Latvian Jews as part of the Holocaust. He never stood trial, however, though there are eyewitness accounts linking Cukurs to war crimes.