Investigators determined Jenner was driving at a speed "unsafe for the prevailing road conditions," Los Angeles County Sheriff's Department spokeswoman Nicole Nishida said.
Jenner was hauling an off-road vehicle on a trailer behind her Cadillac Escalade on Feb. 7 when she steered to avoid cars slowing for a traffic light in front of her on the Pacific Coast Highway in Malibu.
Jenner was unable to stop in time, and her SUV rear-ended two cars, pushing a Lexus into oncoming traffic and also hitting a Toyota Prius. The driver of the Lexus, 69-year-old Kim Howe, was killed when her car was struck head-on by a Hummer.
Daniel W. Vomhof, an accident reconstructionist, said the additional weight from towing a loaded trailer makes it more difficult to stop a vehicle quickly.
Sheriff's officials do not make official recommendations on charges. However, the investigation found enough evidence to support a vehicular manslaughter count, Nishida said.
If convicted, Jenner could face up to one year in county jail.
Investigators will present their findings to the district attorney by the end of August, and that office will determine what, if any, charges Jenner will face.
Jenner's attorney Blair Berk declined comment.
Because Jenner has no prior record, it's unlikely she would face any jail time if convicted, said Vomhof, who's testified in 3,500 cases. He said Jenner would more likely face a fine or probation -- or even an ultimately lesser charge such as driving too fast for conditions.
Vomhof said Jenner's experience towing a loaded trailer may come into play in determining what's ultimately charged, as well as how detailed the police investigation was in recording speeds and distances at the accident scene.
The fatal crash occurred months before Caitlyn Jenner's transition. She was formerly known as Bruce Jenner, the 1976 Olympic decathlon champion and Kim Kardashian's stepfather.
Howe's stepchildren have filed suit against Jenner, claiming they've suffered enormous damages.
The lawsuit by Dana Redmond and William Howe does not specify how much they are seeking. They claim Jenner was negligent when she collided with their stepmother's car, causing them and other relatives "great losses."
Attorneys for Howe's stepchildren, Dana Redmond and William Howe, did not immediately return email messages seeking comment.
Another woman, Jessica Steindorff, who was driving the Prius, also filed suit seeking unspecified damages. A phone message for Steindorff's attorney, Brad Simon, was not immediately returned Thursday.
Jenner's transition has played out in public over the past several months. She's vowed to use her celebrity platform to urge acceptance for others who are transgender.
Jenner may face manslaughter charge
ESPN legal analyst Roger Cossack explains why investigators are recommending a manslaughter charge against Caitlyn Jenner, who was involved in a February auto accident.