But jurors did find Castro guilty on a lesser charge of criminally negligent homicide.
Jurors have a range of punishment of two to 10 years to consider.
The defense is asking for probation while the state is seeking the maximum.
Alexandra Seybert, 24, was stuck in traffic on Highway 281 near TPC Parkway when Castro, who police said was driving more than 90 mph after consuming alcohol at several bars, rammed his pickup into Seybert’s Honda Accord.
Castro’s attorney blamed the initial wreck that halted traffic for the crash that killed Seybert as well as mistakes made by police investigating the crash.
Erica Hernandez is an Emmy award-winning journalist with 15 years of experience in the broadcast news business. Erica has covered a wide array of stories all over Central and South Texas. She's currently the court reporter and cohost of the podcast Texas Crime Stories.