NEW YORK (AP) — A man who killed four people at a Manhattan office building bought the rifle he used in the attack and the car he drove across country from his supervisor at a Las Vegas casino, authorities said Wednesday.

As investigators work to uncover a motive, questions are being raised about how a man with a documented history of mental health problems ended up working in one of the most security-sensitive jobs in Las Vegas.

Court documents shed light on the recent arrest of Philadelphia native and NBA veteran Marcus Morris Sr. after his arrest last weekend.

Marcus Morris' recent arrest now has more details, with TMZ reporting that prosecutors have accused him of stealing $265,000 from Las Vegas casinos.