It all began when I was released from jail, after a two-year conviction for jewel theft.

released 是动词 release 的过去分词形式，在句中表示被动。release 由前缀 re-（表示"重新"）和词根 lease（"放松"）组成，意思是"释放、解除"。这里表示"从监狱被释放"的状态。