Hillary Clinton's brother-in-law was arrested in California at the weekend on suspicion of driving under the influence of alcohol, police said on Monday.Roger Clinton, the half-brother of former president Bill Clinton, was stopped on Sunday evening, Redondo Beach police lieutenant Joe Hoffman said.The 59-year-old actor and musician, who lives in California, spent the night in jail and was released early Monday after posting $15,000 bail, Hoffman said.He is scheduled to appear in court on September 2.Roger Clinton was arrested for drunk driving in 2001. That same year his half-brother pardoned him on a drug charge for which he had served one year in prison.The timing of his arrest was sure to prove embarrassing for the Democratic White House hopeful Clinton, who has been campaigning hard in California ahead of the state's Tuesday primary.The former secretary of state is all but assured of clinching the party nomination on Tuesday to face off in November against Donald Trump, the presumptive Republican presidential nominee.