William Hilton Paul, the 22-year-old son of presidential candidate Rand Paul, was cited for DUI in Kentucky last weekend after rear-ending a parked car.
Authorities said the collision happened just before noon Sunday, when Paul drove his maroon 2006 Honda Ridgeline into the unoccupied vehicle.
A police report described him as being "belligerent" and having "a strong odor of alcohol," bloodshot eyes and slurred speech, according to reports.
A witness said that William had been "revving his engine" prior to the accident; Paul failed a field sobriety test and refused to take a blood test.
He was taken to a nearby hospital for treatment for minor facial injuries.
It's the third time William has clashed with the law over alcohol use. He was previously cited for possession of alcohol by a minor in October 2013.
In January of that same year, William was arrested at a Charlotte, N.C., airport, after becoming intoxicated and disruptive on a U.S. Airways flight.
Rand Paul declared his presidential campaign this spring.
The Republican U.S. Senator's office issued a brief statement only to say he "does not comment on any private matters in regards to his family."
William Paul is due to be arraigned on May 12.