Attorneys delivered their closing arguments yesterday in Chicago’s most significant terrorism trial to date. Federal authorities accuse Chicago businessman Tahawwur Rana of aiding his longtime friend and admitted terrorist, David Headley, in the plotting of the 2008 Mumbai terrorist attacks. Rana’s also accused of helping Headley plot an attack on a Danish newspaper that was never carried out.

The trial, in which Headley testified at length against his old friend, has spanned three weeks. The jury began deliberating this morning.

WBEZ’s Tony Arnold, who’s been following the Rana trial, reviews the key arguments for both sides.