Steven Hansen, 38, of Homeland allegedly carried out at least four unsuccessful attacks targeting law enforcement personnel.
Nicholas Smit, 40, of Hemet is also charged in the case.
In August, a judge severed the two cases, paving the way for the defendants to be tried separately.
Smit's case is expected to go before a jury later this month. He is charged with three counts of attempted murder of a peace officer, two counts each of assembling and placing a booby trap and being in possession of a zip gun, as well as conspiracy to commit murder of a peace officer, attempting to ignite a destructive device with the intent to kill, and enhancements for allegedly having a rocket-propelled weapon and discharging a firearm.
Hansen is charged with one count each of attempted murder of a peace officer, conspiring to murder a peace officer and attempting to ignite a destructive device with the intent to kill.
Both men are being held without bail.
The Hemet Police Department invested thousands of dollars to step up security at its Latham Street station after the repeated attacks. The improvements include surrounding the building with wrought iron fencing and the installation of floodlights, surveillance cameras and windows with bullet-resistant coating.