* A base level of 14 for an obstruction of justice charge (§2J1.2)
* -2 for acceptance of responsibility (§3E1.1)
Assuming no previous criminal history, that's a guideline sentence of 10-16 months. If he can get it down one more point to a level 11 sentence, that's a Zone B sentence and can be entirely served on probation.
The DoJ press release is at https://www.justice.gov/usao-cdca/pr/santa-barbara-county-ma..., but the plea agreement isn't available (yet), which would indicate if they've agreed on an offence level and any adjustments.
EDIT: Found the plea agreement; see comment in thread
* Harmed or threatened to cause harm to a person or property damage
* Substantial interference with administration of justice
* Extensive in scope, planning, or preparation
Minus the guilty plea, he could be looking 4-5 years.