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A government investigation into confusing gear shifters like the one in the SUV that crushed and killed Star Trek actor Anton Yelchin found 266 crashes that injured 68 people.

The numbers are in documents posted Tuesday on the U.S. National Highway Traffic Safety Administration website. The agency closed the investigation last Friday after Fiat Chrysler agreed to recall 1.1 million vehicles.

Investigators also found 686 consumer complaints about the shifters and said that Fiat Chrysler received negative customer feedback shortly after the vehicles went on sale. The company also appeared to violate basic design guidelines for vehicle controls with the shifters, according to the agency.

Read More: 'Star Trek' Actor Anton Yelchin Dies in Freak Car Accident at Age 27

Yelchin, 27, known for playing Chekov in the rebooted series, died June 19 after his 2015 Jeep Grand Cherokee pinned him against a mailbox pillar and fence at his home in Los Angeles. Police are investigating.

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His Jeep was among vehicles recalled in April due to complaints from drivers who had trouble telling if they put the transmission in "park" after stopping. Many reported the vehicles rolled off after the driver exited.

The vehicles now sound warning chimes and alert messages if the driver's door is opened while the engines are running and the cars are not in park, FCA said in a statement Tuesday. It urged customers to set parking brakes before exiting their vehicles, and to follow instructions in owners' manuals and information cards that were mailed by the company.

Last week, FCA said it would speed up the global recall. The safety agency mentioned the Yelchin case in its documents as possibly being related to the shifters. He was not named in the documents.

Read More: Anton Yelchin Death Highlights Concerns About Electronic Shifters

FCA has said that it began providing its 2,427 dealers with a software update shortly before Yelchin died. Previously the company had said the update would be ready in July or August.

Yelchin may have received a letter warning him about the problem. The documents posted Tuesday said such letters were mailed out by FCA on May 14 with instructions telling owners to make sure their vehicles are in park and the parking brake is on before they exit.

Last week, Fiat Chrysler said it would start sending letters to owners on June 24 telling them to make a service appointment. Safety advocates have questioned why the fix was taking so long.