California: High failure rate results in failure of Lake County Sheriff recall

The attempt to recall Lake County Sheriff Frank Rivero failed, with a very high failure rate. Petitioners needed 7,026 signatures. They handed in 7,778, but only 5,715 were found valid. They article has the most detailed breakdown I've ever seen of why signatures failed:

Signatures of those not registered to vote totaled 668 (8.6 percent).
People who signed petitions more than once amounted to 250 (3.2 percent).
Two people withdrew signatures (0.0 percent). Those who registered late: 35 (0.4 percent).
Registered at a different address: 529 (6.8 percent). People who could not be identified: Five (0.1 percent)
Incomplete declarations totaled 71 (0.9 percent). No residence address given: 119 (1.5 percent).
There was no signature on 29 (0.4 percent) of the declarations.
Signatures that didn't match accounted for 42 (0.5 percent).
Incomplete residence address: 12 (0.2 percent).
Signature label used: 1 (0.0 percent).
Circulator inactive: 52 (0.7 percent)
Add written by someone else accounted for 248 (3.2 percent).