It is a separate crime
Under Penal Code 1320.5, willfully failing to appear while released on bail in a felony case is itself a felony, with its own sentence, prosecuted separately from the original charge. See PC 1320 vs PC 1320.5.
The people who signed pay for it
- The court declares the bond forfeited and the surety has to pay the full face amount if the defendant is not returned within the statutory appearance period.
- The indemnity agreement makes the cosigner liable for that amount plus recovery costs.
- Collateral — a car title, a deed of trust on a house — is exactly what it sounds like at that point.
- The relationship between the defendant and the person who vouched for them rarely survives it.
It ends the good outcomes in the original case
Diversion, deferred entry of judgment, reduced charges — the paths that resolve a case without custody all depend on the defendant looking like a person who complies. A bench warrant closes those doors, and any later bail becomes far harder to obtain because the court now has evidence on the flight question.
Recovery is real
California permits bail fugitive recovery, subject to licensing and notice requirements. The idea that a person disappears and nothing happens is fiction — see does California have bounty hunters.