A 20-year-old man who allegedly held up a tourist couple at gunpoint when they ran out of road at Yokohama Bay last week has been arrested on suspicion of various robbery, firearm and drug offenses.

The tourists were trying to drive a rented Saturn around O'ahu on May 22 when Farrington Highway ended and they found themselves on an undeveloped road headed toward Ka'ena Point, according to a police probable cause affidavit.

The driver turned around but was stopped by a man in a dark T-shirt and shorts who reached into the car and tried to unlock the driver's side door, according to the affidavit.

He pulled out a handgun, ordered the driver and his wife out of the car and drove off, stopping about 100 yards away to pick up another man, according to the affidavit.

Crime Reduction Unit officers later found the man who was picked up, who identified the suspect, the affidavit said.

On May 25, Crime Reduction Unit officers found the suspect at Kea'au Beach Park standing next to a blue Ford Escort he's known to drive.

Inside the car, police found the victims' passports, credit cards bearing the wife's name, German currency, two glass pipes containing white residue that resembled methamphetamine, a plastic bag with a substance that resembled methamphetamine, six rounds of .22-caliber ammunition and two .22-caliber casings.

In the engine compartment, officers recovered a .22-caliber rifle with a scope.

Reach Dan Nakaso at dnakaso@honoluluadvertiser.com.