It's not at all the way most American's expect to see a member of the Kennedy family.
Tuesday night in Bedford, there was mostly sympathy from residents, who called the incident "very sad."
Mary Kennedy is married to Robert Kennedy Jr.
Police say Kennedy had a blood alcohol level of 0.11, which is over the legal limit of 0.08.
In the last week, police have been to the Kennedy home in Bedford on two other occasions.
In one of the incidents, police filled out a state domestic incident report, but say there were no crimes committed.
That incident was unrelated to Mary Kennedy's arrest.
Eyewitness News contacted the Kennedy family for a statement, but there was no response.