What is the name of the person Cassander placed on trial for murder?  Answer the above question based on the context below:  When Alexander the Great died at Babylon in 323 BC, his mother Olympias immediately accused Antipater and his faction of poisoning him, although there is no evidence to confirm this. With no official heir apparent, the Macedonian military command split, with one side proclaiming Alexander's half-brother Philip III Arrhidaeus (r. 323 – 317 BC) as king and the other siding with the infant son of Alexander and Roxana, Alexander IV (r. 323 – 309 BC). Except for the Euboeans and Boeotians, the Greeks also immediately rose up in a rebellion against Antipater known as the Lamian War (323–322 BC). When Antipater was defeated at the 323 BC Battle of Thermopylae, he fled to Lamia where he was besieged by the Athenian commander Leosthenes. A Macedonian army led by Leonnatus rescued Antipater by lifting the siege. Antipater defeated the rebellion, yet his death in 319 BC left a power vacuum wherein the two proclaimed kings of Macedonia became pawns in a power struggle between the diadochi, the former generals of Alexander's army.A council of the army convened in Babylon immediately after Alexander's death, naming Philip III as king and the chiliarch Perdiccas as his regent. Antipater, Antigonus Monophthalmus, Craterus, and Ptolemy formed a coalition against Perdiccas in a civil war initiated by Ptolemy's seizure of the hearse of Alexander the Great. Perdiccas was assassinated in 321 BC by his own officers during a failed campaign in Egypt against Ptolemy, where his march along the Nile River resulted in the drowning of 2,000 of his men. Although Eumenes of Cardia managed to kill Craterus in battle, this had little to no effect on the outcome of the 321 BC Partition of Triparadisus in Syria where the victorious coalition settled the issue of a new regency and territorial rights. Antipater was appointed as regent over the two kings. Before Antipater died in 319 BC, he named the staunch Argead loyalist Polyperchon as his successor, passing over his own son Cassander and ignoring the right of the king to choose a new regent...
Answer:
Olympias