BOISE, Idaho -- Idaho Senate Republican Caucus Chairman John McGee was arrested early Sunday after police say he took a Ford Excursion and cargo trailer from the Boise home of a "complete stranger" and a blood-alcohol test showed the four-term lawmaker had been drinking.

The lawyer for the 38-year-old senator, who represents Caldwell and is the head of the Canyon County GOP, says McGee is embarrassed by the situation and intends to handle his legal case responsibly.

McGee was being held in the Ada County Jail pending an arraignment in 4th District Court on Monday afternoon. Authorities say he was taken into custody on suspicion of felony grand theft and misdemeanor driving under the influence after a breath test found he had a blood-alcohol content of 0.15 percent, nearly twice the legal limit in Idaho.

"He is embarrassed by this matter. He has never been in this situation before, but he has great confidence in the criminal justice system," said attorney Scott McKay, who met with McGee on Sunday. "With the love and support of his family, he will handle this matter responsibly," McKay said in a statement.

So far, police have released only a few details of events preceding McGee's arrest. But Lt. Kody Aldrich told The Associated Press that McGee did not know the owner of the SUV and trailer that he was driving and later was found by police sleeping inside. The vehicle and trailer became stuck as McGee tried backing into the yard of a home on southwest Boise. It was also unclear why McGee was in the Boise area in Ada County.

"Nobody knows why he was there," Aldrich said. "It doesn't sound like he did either."

Aldrich said McGee told officers he was on his way to Jackpot, Nev. Police were alerted of McGee's actions by people who lived inside the home.

Aldrich said the vehicle's owner typically left the keys in the steering column and the doors unlocked.

Because McGee faces a potential felony charge, he will be held in jail until he goes before a judge, Aldrich said.

Messages left by the AP at McGee's home and cell phone were not returned Sunday.

Idaho Senate Pro Tem Brent Hill, R-Rexburg, expressed support and said the immediate concern is for his colleague and his family.

"We feel really bad about the situation and how it may affect his wife and family," Hill, the GOP leader of the Senate, told the AP. "Our concerns right now are to help him and his family out any way we can. We just want to make sure things work out for John and his family."

Aldrich said McGee jackknifed the SUV and trailer attempting to back up, entering a yard and becoming stuck. Aldrich said the trailer and vehicle sustained minor damage, and that McGee was not injured.

McGee, who is married and has a daughter, in 2006 was named the Idaho Young Republican of the Year and Republican Legislator of the Year.

The senator from District 10 is the marketing director for West Valley Medical Center. He serves on the three Legislative committees: local government and taxation, state affairs, and transportation.

In the last Legislative session, McGee supported Gov. C.L. "Butch" Otter's "Hire one Act" that offers employers tax credits as a way to encourage them to add more workers. McGee also supported a bonds-for-highways plan called "Connecting Idaho" intended to maintain Idaho's roads and bridges.

Also last session he introduced a bill requiring underage drivers to take safety training as part of a compromise to fend off road closures and maintain public access following a U.S. Forest Service plan to close some roads to all-terrain vehicles amid safety concerns over underage drivers.

McGee also supported a measure giving immunity from lawsuits to doctors who recommend that a patient's driver's license be revoked, arguing doctors must be allowed to recommend drastic action without fear of legal repercussions. McGee also supported legislation to ban texting while driving.