Complex sentence: Starr began using his client's assets improperly, and even fraudulently had one of his clients give him a power of attorney to control her assets, depleting them in various high-risk investments and by paying bills.
Split into simpler sentences: Starr began using his client's assets improperly, and even fraudulently had one of his clients give him a power of attorney to control her assets. He then depleted the assets by making various high-risk investments and by paying bills.