This was decades before stories of Area 51 or UFOs were commonplace, but on Sept. 3, 1912, Johnstone's vehicle was mysteriously ensnared by something from above.
This saga actually began many miles to the west in Venice where the famous Ocean Park Pier was reduced to ashes by a huge fire earlier in the day.
One of Ocean Park's attractions was a tethered gas balloon that gave passengers an aerial view of the Venice coastline from a height of 100 feet or more.
Firefighters, fearing the gas balloon might explode during the blaze, cut it loose. And shortly after dark, the balloon and its grappling hook met Assemblyman Johnstone's rear bumper.
"He suddenly felt his auto lifted upward in the rear. He thought it rather uncanny and was surprised," was the rather understated account in the Pomona Daily Review the next day.
Johnstone unhooked the alien balloon and got his car's rear wheels back on the ground.
The wayward balloon was sent off again, only to cause more mayhem when it hooked a Pacific Electric trolley cable just west of San Dimas. It halted all trains on the route until repairs could be made.
BEING A police chief in the Inland Valley of years ago was a lot different than today, and dangerous.
Chiefs, such as Pomona's Henry P. Tracy, found themselves all too often in the midst of the action.
Tracy was shot in the leg while pursuing a suspicious character on the night of July 22, 1914.
On that night, Tracy and another officer were patrolling in downtown Pomona when they saw three Latinos standing suspiciously in front of a department store.
As Tracy tried to question them, one took off running.
"I yelled, `Stop or I'll shoot you,"' Tracy recalled the next day. "He suddenly blazed away with this revolver. I suppose he was trying to scare me."
Two shots missed but a third proved more than scary, striking him below the knee. He crashed to the ground.
To his credit, the dazed and wounded Tracy dragged himself for two blocks to make sure his other officer was safe.
The shooter disappeared and was never arrested.
Tracy was hobbled for some time with the bullet in his leg, needing a cane to get around for months.
Having recovered, Tracy became the only Inland Valley police chief to die on duty. On May 3, 1915, he hitched a ride on the back of one of the police motorcycles. It was struck on West Second Street by a truck hauling oranges, killing the chief.
A MOST BIZARRE arrest occurred in San Bernardino in 1936 when police nabbed Samuel Frank, who had more than just the law pursuing him.
In February, he had received national attention when he appealed to Texas Gov. James V. Allred to help him find a wife. That got him 13,000 offers of marriage from women.
What was obvious, however, is that larceny rather than matrimony was mostly on his mind.
Frank came to the Inland Empire while on the lam from the Bay Area where Louisa Kennedy of Berkeley charged him for leaving town with $126 he "borrowed" from her, reported the Ontario Daily Report on Aug. 4, 1936. It appears she got most upset when she found him making time with another of the 13,000 "applicants."
Frank headed south only to run afoul of the law in Los Angeles. Moving on to San Bernardino under the name of Frank Gould, he was captured and returned to the Bay Area.
Before he made it to court, another of his admirers, Ida May Peck of El Cerrito in Contra Costa County, tried to bail him out.
"I'll stick to him until the end," Peck said. "I love him."
Frank's attraction is tough to understand.
"Mrs. Peck sure must like Frank," said Oakland Police Inspector Robert Tracy.
"Frank told me himself that of all the women he knew, he mistreated Ida May the most. He pawned her diamond ring for $15, told her to mortgage her furniture and then sold her furniture to a second-hand dealer for $50 and he kept all the money."
What a catch that Frank was.
Joe Blackstock writes on Inland Valley history. He can be reached at 909-483-9382, email@example.com or @JoeBlackstock