Complex sentence: As he grew older, his skills in thievery grew until he became a thug successful enough to break into other people's homes for their valuable property until he was finally caught one by the authorities during one of his burglaries and imprisoned.
Split into simpler sentences: As he grew older, his skills in thievery grew until he became a thug successful enough to break into other people's homes for their valuable property. He was finally caught one by the authorities during one of his burglaries and imprisoned.