Police spokesman Lt. Robert McCullough says investigators determined that Rice didn't get special treatment and that there was no quid pro quo for the autograph.
Rice had posted a statement on Twitter that suggested he got out of a ticket in exchange for the autograph.
According to the Baltimore Sun, the tweet read: "Just got pulled over for my tints smh [shaking my head] But gave the officer a autograph for his son and he let me go."
He deleted the post and later said it had been poorly worded.
McCullough says the officer verbally warned Rice that the tint on his white Range Rover's windshield was darker than the law allows. It's not unusual for officers to issue warnings in such cases, allowing people to remove the tint and avoid a citation.