I retract my earlier statement that the Prius had already collided with another vehicle. That was the initial claim.
Here is how the DA's Office ruled:
"The Los Angeles County District Attorney's Office issued an investigation into the accident and looked into the possibility of vehicular manslaughter. The investigation triggered controversy for Jenner at the time, because the misdemeanor charges would have potentially put her behind bars for at least a year, at which point she had just announced her gender transition.
At the end of the investigation, the DA's office did not proceed with charges due to a lack of evidence. In order to prove vehicular manslaughter, a person must have some level of ordinary negligence. In Jenner's case, they came up empty. The Los Angeles County Sheriff's Department recommended that she be charged, however it wasn't their final decision.
In addition to a lack of evidence, the DA's report said Jenner let go of the gas pedal and engaged her brakes a couple of seconds too late before hitting Howe. The report says she did not break any traffic laws, except for driving below the speed limit. Therefore, they declined to charge her with vehicular manslaughter.
Experts say charging someone for the crime isn't easy. The burden of proof is entirely on the prosecution. California law says the prosecution must prove that the person who caused the death was driving with negligence and violating traffic laws."
https://www.capradio.org/articles/2021/05/10/was-caitlyn-jenner-released-by-a-district-attorney-after-killing-someone/