Steven Senne, File, Associated Press
FILE - In this Feb. 9, 2010 file photo, Rhode Island House Minority Leader, State Rep. Robert Watson, R-East Greenwich, is seen during a session in the House Chamber at the Statehouse. Watson said Monday, Jan. 23, 2012, that he has checked into in-patient rehabilitation following his second arrest on marijuana possession charges Saturday, Jan. 21, 2012 in South Kingstown, R.I.

PROVIDENCE, R.I. — Rhode Island state Rep. Robert Watson has checked into inpatient rehabilitation following his second arrest on marijuana possession charges in nine months.

The former House Republican leader was arrested early Sunday in South Kingstown.

State GOP Chairman Mark Zaccaria says Watson's decision to enter a residential rehab program shows he's taking steps to address his problem.

Police say a snowplow operator reported Watson was driving erratically on a flat tire late Saturday. Police say they found a pipe used to smoke marijuana and suspected marijuana.

Watson is awaiting trial in Connecticut on charges of marijuana possession, possession of drug paraphernalia and driving under the influence. He has pleaded not guilty.

Watson's attorney in that case says it's too soon to know if the most recent arrest will have an impact.