Normally the bus simply sped by, but on this day it crawled to a near-stop right in front of his black Volkswagen Jetta.
Near the front of the bus, a girl in a white T-shirt -- who looked to be about ten years old -- reached out the window, held a plastic Gatorade container aloft and proceeded to dump the watery contents over the Jetta.
"I was utterly astonished. I absolutely couldn't believe it," says the 36-year-old Crocker.
He ran back into the house, grabbed his keys, jumped into his car and raced after the bus.
"The kids were gathered near the back of the bus, flipping me off," Crocker recalls. "The bus driver looked like he was trying to get away, but he got caught behind traffic at Dale and McCausland."
Crocker got out of his car and knocked on the bus' door. The driver opened it.
"You've got kids throwing Gatorade on my car!" yelled Crocker.
The driver asked him who did it, and Crocker took a step onto the bus and immediately recognized the white-shirted girl. "That kid right there!" he said.
"You'll have to take it up with Atlantic," said the driver, referring to the company that owns the fleet of buses. Crocker grudgingly left the scene.
When he got back home, he called the cops. An officer came to make a report and, in the process, noted that the Gatorade jug was blue, but the liquid dumped from it was yellow.
"That's urine," said the officer after giving Crocker's car a cursory smell-check.
This was neither the beginning nor the end of Crocker's problems with the renegade school bus. A student at St. Louis Community College-Forest Park and Central Missouri State University, Crocker says he's had numerous study sessions disrupted by the bus barreling down Yale in front of his sea-foam-green house. He says he's trailed the bus and clocked it going anywhere from 35 to 45 miles per hour. The speed limit is 25 mph.
"I was astounded by how fast that felt," he says.
The full-size bus rolls by every afternoon between 2:35 and 2:50 with the regularity of Old Faithful, says Crocker. The walls rattle. Potholes don't slow down the driver, who Crocker speculates is perhaps nearing the end of his shift and is trying to beat rush-hour traffic.
"The paint is chipping," says Crocker, gesturing toward a decaying area where the wall meets the ceiling of the otherwise fastidiously kept house.
Crocker isn't the only one bothered by the daily menace-on-wheels.
"I was cutting my grass one day, and it went flying up the street real fast," says one elderly neighborhood resident who, concerned about potential repercussions, asked not be identified in this story. "I hope nobody's crossing the street or anything. They wouldn't have much of a chance."
Crocker bought his home in 1998 in what he thought was an idyllic neighborhood. "It was as quiet a neighborhood as I could get, I thought, without moving to the suburbs," he says. Previously a salesman who hocked data-storage items to the federal government, Crocker took the advice of his wife, Suzanne, and began pursuing his dream of becoming a pediatric dietician two years ago.
He started spending a lot of time at home preparing presentations and studying for exams. And in the fall of 2003, he began noticing the school bus recklessly rolling by -- every single school day.
"I didn't want to sound like a crotchety old man," says Crocker, "but I waved the driver down and asked him if he knew the speed limit."
Crocker doesn't remember exactly what the driver said back to him, but he left the scene feeling confident that his concerns were over.
But no: The speeding continued for months, and he believes the bus is still helmed by the same lead-footed driver.
So in March -- just a few days before the urine incident -- Crocker called the Staten Island, New York-based Atlantic Express and spoke to someone in charge of bus safety.
"The guy sounded enthusiastic about handling the situation," remembers Crocker of the person who identified himself as a member of the company's safety division. "He said he'd take care of it, that they'd put the driver through safety training."
Atlantic Express general manager Ernie Bellinger says this is the first he's heard of the problem.
"We'll have one of our safety supervisors go down there and see what's going on. We don't want buses speeding through neighborhoods -- that's not what we do."
Bellinger declined to identify the school bus driver. Regarding the pee-flinging, he remarks: "That is a highly unusual situation -- if it happened."
All this is cold comfort for Crocker, who remains skeptical that anything will be done. "I wonder what else they'll do to our cars, to our property?" he says, noting that he and his wife both park their cars on the street.
Crocker sighs. "I'm not a crotchety old man, I swear."