Complex sentence: In January 1998, he spent a week in rehab to deal with an addiction to prescription analgesics; a week following his release, he was arrested for an unlawful use of a handgun and possession of cannabis.
Split into simpler sentences: In January 1998, he spent a week in rehab to deal with an addiction to prescription drugs. A week following his release, he was arrested for an unlawful use of a handgun and possession of cannabis.