The driver of a box truck who failed to stop for slowing traffic on the Maine Turnpike in November, killing a man and a boy when he crashed into the car ahead of him, concealed his history of diabetes to obtain the medical clearance required to drive, federal investigators found.

In documents obtained by the Portland Press Herald, federal investigators with the Motor Carrier Safety Administration describe how John K. Kamau, 56, of Lowell, Massachusetts, was informed by his medical provider in May 2016 that because he is an insulin-dependent diabetic, he was no longer permitted to drive across state lines.

But instead of complying with the finding or seeking an exemption under federal rules, investigators say, Kamau went to a different doctor four months later, concealed his diagnosis – a crime under federal law – and received a medical clearance to drive. Investigators did not describe how they knew that Kamau went to a different doctor.

Falsifying the federal medical documents carries a $10,000 fine, which can be increased to $105,000 if it is determined the violation resulted in death.

Insulin-dependent diabetes is a disqualifying condition for a commercial driver because the onset of diabetic shock can render the driver unconscious without warning.

Any Maine driver with diabetes must get checked out by a doctor at least once before being licensed. Those who control diabetes with medication, such as insulin or pills, have to be re-evaluated once every eight years, with more intense levels of medical scrutiny at their doctors’ discretion.

For the same safety reasons, insulin use had been a universally disqualifying factor for commercial airline pilot licenses until 2015, when the Federal Aviation Administration developed a case-by-case exception process.

The federal documents, known as a declaration of imminent hazard, do not name the doctors or medical practitioners involved in the case, and investigators never say that the crash in Wells was caused by Kamau’s diabetes, only that he was not qualified to drive an interstate truck at the time of the wreck.

Kamau did not respond to multiple messages left on his cellphone and at his business number.

The declaration of imminent hazard also cited Kamau’s long history of unsafe driving.

According to federal investigators, Kamau has at least 11 convictions for speeding, five convictions for unsafe lane changes and seven convictions for failing to obey or stop at stop signs.

On Dec. 20, regulators shut down Kamway Services, a one-man operation run by Kamau, finding that Kamway’s violations of safety regulations – including a failure to maintain basic safety records – were so egregious that allowing the company to continue operating would present an imminent hazard to public safety.

In a 2014 crash that was similar to the fatal crash on Nov. 18, Kamau was cited for failing to stop his truck in slowing traffic along Interstate 95 outside Westwood, Massachusetts, slamming into the back of a passenger car.

In that situation, a woman in a 2004 Toyota slowed down in morning rush-hour traffic. When she saw Kamau’s truck behind her approaching at high speed, she swerved into the breakdown lane in an attempt to avoid being hit, according to the Massachusetts crash report.

But Kamau swerved, too, and hit the car. No one was hurt, but Kamau was issued a written warning for failure to use care in stopping, according to the Massachusetts police report on the crash.

During a search of Kamau’s truck after the fatal turnpike crash on Nov. 18, investigators found a medical cooler in the cab, containing a bottle of insulin, syringes and a blood sugar test kit, according to search warrant documents.

Kamau declined to be interviewed by investigators after the crash, invoking his Miranda rights to have an attorney present. But he did make a spontaneous statement at the roadside to the accident investigator, according to search warrant documents.

“I saw the car and I couldn’t do anything, so I closed my eyes,” Kamau told Trooper Gavin Hager, according to the court papers. “Kamau made a gesture of putting his arms towards his face,” Hager stated.

SIGN WARNED OF TRAFFIC SLOWDOWN

In addition to a search of Kamau’s truck, a judge approved a vehicle autopsy, which was requested to help investigators determine whether a failure of the truck’s brake system contributed to the crash that killed Earl Gray, 57, of Waterboro, and Gray’s 5-year-old passenger, Wyatt Frost.

The results of the crash investigation will be forwarded to the York County district attorney, who will determine whether criminal charges are warranted.

Kamau was driving north on the turnpike, carrying a load of DHL packages and letters from New Hampshire to Portland, when the traffic ahead of him began to slow down around Mile 22 because of an accident a few miles up the road.

Michael Coolong, 59, was driving a tractor-trailer that was two vehicles ahead of Kamau’s truck. Coolong, a longtime commercial driver, was returning his truck to Portland and his 48-foot trailer was nearly empty, loaded with only a couple of rolls of bubble wrap.

In an interview with the Press Herald, Coolong said he saw the flashing warning lights on a road sign that informed him of heavy traffic ahead, and tuned to the AM radio station to hear details.

The cars around him started to slow.

“When that light starts flashing, everyone starts slowing down,” Coolong said. “I could see for a couple miles ahead of me, all kinds of brake lights.”

It was slow going, he said.

“We were moving along about 15, 20 miles an hour. I was sitting there eating my Fritos, riding along, and I then I got slammed into.”

Coolong said the impact was so great that it broke the rear axles of his truck, forcing the trailer wheels forward. The whole rig, cab and all, was pushed at least 20 to 30 feet down the road, he said. He estimated that, given the damage to his own trailer, Kamau must have been going about 70 mph.

“He was at full bore. The only skid marks there was me,” Coolong said. “I put my brakes on so I didn’t hit the car in front.”

WITNESSES: DRIVER DIDN’T CHECK ON VICTIMS

A witness interviewed by police estimated that Kamau was driving between 60 mph and 80 mph.

When Coolong got out of his truck to see what had happened, he could hardly see the 2011 Nissan driven by Gray, which was partially wedged under the rear bumper of his trailer. The rear of the car was covered by Kamau’s truck, which had ridden up on top of the smaller vehicle.

“It didn’t look like there was a car back there, it was that bad,” he said.

The Nissan appeared to explode into pieces, a witness told police.

Although other drivers and passengers on the road nearby reported hearing a quick braking sound from Kamau’s truck, a state police accident reconstruction specialist found no evidence of tire marks left on the dry pavement by the 2008 Hino box truck.

According to Coolong and another witness interviewed by police, Kamau got out of the truck immediately after the crash, already on his cellphone.

As witnesses and the driver of the tractor-trailer in front of the Nissan tried to render first aid to Gray and Frost, Kamau walked to the back of his truck, opened the rear rolling door and waited by the side of the road.

Coolong said Kamau should have had plenty of warning that traffic was slowing down.

“There was no reason he couldn’t stop,” Coolong said. “The part that really bothered me the most, not one time did he go to the other car. He got out of the (truck), talking on the phone, and went to the back of his truck and opened his back door. Not once did he go to the other car, see if they were OK or needed help.”