The witnesses standing on the fishermen’s pier at the Port of Los Angeles could hear the tires screech just before the ’98 Honda Civic hurtled toward the ocean.

It was April 9, 2015, and Ali Elmezayen was at the wheel. His two autistic children, ages 8 and 13, were strapped in tight in the back seat, and their mother was in the passenger’s seat — screaming for Elmezayen to hit the brakes.

“Stop! Stop!” Rabab Diab remembered yelling. But Elmezayen didn’t say anything, and he didn’t stop. The car plunged off the edge of the wharf, crashed into the harbor and immediately began sinking.

Elmezayen, however, emerged within seconds. His window was open. He swam to the dock as bewildered fishermen looked on, and as he began climbing up a ladder his domestic partner, Diab, emerged too. She was flailing in the water and hysterically yelling, “My kids! My kids!” But Elmezayen just stood there, witnesses later told investigators. The fisherman tossed Diab an inner tube.

By then, her kids were trapped 20 to 30 feet underwater. They died shortly after divers from the Los Angeles Fire Department rescued them from the ocean floor.

It all seemed like a horrible accident at first, or at least that is what Elmezayen told the news media and police. He said in his police interview that night that he didn’t know how or why he drove off the wharf. He suggested he might have passed out on medication he was taking, or might have accidentally hit the gas rather than the brakes, or maybe he had an “evil inside of me that pushed me to go,” according to a federal affidavit.

But federal prosecutors said Tuesday that Elmezayen knew exactly what he was doing that April night: They say he drove off the bridge on purpose to kill his family, and it was all part of a scheme to collect on the millions of dollars in seven life insurance policies he had taken out on their lives. It was a plan he had been plotting for more than two years, according to prosecutors.

“This case alleges a calculated and coldhearted scheme to profit off the deaths of two helpless children,” Nick Hanna, U.S. attorney in the Central District of California, said in a statement Tuesday. “The alleged conduct shocks the conscience, and we will use every tool available to us to ensure that justice is done.”

Elmezayen is charged with mail fraud, wire fraud and aggravated identity theft, for allegedly pretending to be Diab when presenting himself to insurance companies. The Los Angeles County District Attorney’s Office declined to charge Elmezayen in his sons' deaths for insufficient evidence, the Associated Press reported. Salt water appeared to corrode the brake pedal as the vehicle sat in storage, police said, making it difficult to determine whether the brakes were working at the time of the plunge.

An attorney for Elmezayen did not immediately respond to a request for comment, but Elmezayen has maintained the brakes failed him. He was ordered detained without bail Tuesday. Prosecutors argued he poses a danger to his family, because although he and Diab separated a week after the tragedy, he is still paying premiums on her life insurance and on the insurance of his third son. The boy was away at camp on the night his siblings drowned.

Elmezayen and Diab’s story began in Egypt, where they started dating before coming to the United States on six-month visitor visas in 2000. But instead of returning, they settled down in California and had three sons together, each of them autistic. An immigration judge later ordered Elmezayen and Diab removed, but each was granted “withholding of removal,” according to the federal prosecutors.

In an attempt to remain in the country legally, Elmezayen entered into a sham marriage with an American citizen he met while working as a security guard at a Los Angeles drugstore, according to a 2006 interview he gave to immigration authorities. The sham wife lived in an alcohol treatment center, and the deal was that she would marry Elmezayen so he could get a green card as long as he continued to financially support her once he obtained it. He never did. In four years, he paid the woman $500, he told authorities. (They later divorced.)

Money never seemed to come easy for Elmezayen, who filed for bankruptcy in 2010 and had been earning less than $30,000 annually, prosecutors said. But somehow he found the money to take out seven different accidental death and life insurance policies on his family’s lives.

In total, he took out more than $6 million in policies, costing him $6,000 a year in premiums, according to prosecutors.

Diab said in a deposition in 2017 that she knew about the policies for both her and Elmezayen — but not the children. (The deposition was part of a wrongful-death lawsuit she and Elmezayen filed against Honda, Jiffy Lube and Los Angeles County. They lost.)

Elmezayen frequently called the insurance companies posing as Diab, according to prosecutors. The companies typically had policies requiring that if a person died less than two years after insurance was taken out on his or her life, then the companies would investigate the deaths before making payouts. So Elmezayen, in recorded calls to the companies, kept double-checking: Would the companies still want to investigate even after two years? Or would he just get the money?

“What happened if [someone died] one day before two years?” he asked the insurance representative, who confirmed that the company would still investigate, according to the affidavit.

“Oh, okay. The difference two years or not two years is you investigate it. You try to find out how I die. Right?” Elmezayen asked.

Twelve days after the two-year period expired on the last life insurance policy he had purchased, Elmezayen barreled down the wharf and into the ocean. In a matter of months, he collected more than $260,000 on his sons' lives, according to the affidavit. He wired $171,000, the bulk of the money, to Egypt.

Elmezayen denied having any life insurance policies on his children in interviews with police on the night of the plunge.

Just after the interview ended, Elmezayen met Diab in the hallway and tried to assure her everything would be okay. She had just finished her interview, too.

“What did you tell them?” Elmezayen quietly asked her in Arabic, apparently unaware he was still being recorded, according to the affidavit.

“Nothing,” Diab said. “The car lost control and fell into the ocean.”

Elmezayen said that was great, and then Diab wanted to know, were their two sons still in the hospital?

“Yes, Rabab,” Elmezayen said. “May God compensate us for the kids. ... May God give us better than them.”

More from Morning Mix: