In order for someone to be found guilty of a Criminal Threat, the person being threatened needs to feel that you would carry out that threat and that its not just talk. That's one defense that you may have. Secondly, the threatened person needs to be in fear of his safety. If your friend never called the police and says he doesnt want to pursue this, you may have a defense on that issue as well.
You need to be careful when you accept a plea bargain on this charge (criminal threats, PC 422) because if its filed as a felony, it is a strike (under california's 3 strikes law). That means that if you pick up another felony, it automatically will double your sentence and make you ineligible for probation.
Final word of advice is if you feel police officers have it in for you, maybe its time to tone it down or move. Otherwise you are always going to be someone they stop and question, especially if they put you on probation after this case.
You have a very interesting case and there seem to be many legal and factual issues raised. Without more information though I cannot address them. I will answer your main question. If someone is convicted of Penal Code Section 422 which addresses threats, they could receive up to 1 year in the county jail if it is charged by the District Attorney as a misdemeanor or up to 3 years if charged as a felony. Of course many factors affect how much time, if any, to which a person is sentenced.
If you are convicted of Penal Code section 422 as a misdemeanor - the maximum is 1 year in the county jail and a firearm ban.
If you are convicted of Penal Code section 422 as a felony - the maximum is 3 years in state prison, it is a strike,and a serious felony.
Here is some other useful information:
For the purposes of California Penal Code Section 422, "immediate family" means any spouse, whether by marriage or not, parent, child, any person related by consanguinity or affinity within the second degree, or any other person who regularly resides in the household, or who, within the prior six months, regularly resided in the household.
"Electronic communication device" includes, but is not limited to, telephones, cellular telephones, computers, video recorders, fax machines, or pagers. "Electronic communication" has the same meaning as the term defined in Subsection 12 of Section 2510 of Title 18 of the United States Code.
Judicial Council of California Criminal Jury Instruction, (CALCRIM) 1300, states:
To prove that someone is guilty of having made a criminal threat in violation of California Penal Code section 422, the Prosecution must prove beyond a reasonable doubt each of the following elements:
1. The defendant willfully threatened to unlawfully kill or unlawfully cause great bodily injury to the complaining witness or a member of the complaining witness's immediate family;
2. The defendant made the threat (orally or in writing or by electronic communication device);
3. The defendant intended that her statement be understood as a threat and intended that it be communicated to the complaining witness;
4. The threat was so clear, immediate, unconditional, and specific that it communicated to the complaining witness a serious intention and the immediate prospect that the threat would be carried out;
5. The threat actually caused the complaining witness to be in sustained fear for his own safety (or for the safety of his immediate family);
6. The complaining witness's fear was reasonable under the circumstances.
Someone commits an act willfully when he or she does it willingly or on purpose.
In deciding whether a threat was sufficiently clear, immediate, unconditional, and specific, consider the words themselves, as well as the surrounding circumstances.
Someone who intends that a statement be understood as a threat does not have to actually intend to carry out the threatened act or intend to have someone else do so.
Great bodily injury means significant or substantial physical injury. It is an injury that is greater than minor or moderate harm.
Sustained fear means fear for a period of time that is more than momentary, fleeting, or transitory.
An immediate ability to carry out the threat is not required.
An electronic communication device includes, but is not limited to: a telephone, cellular telephone, pager, computer, video recorder, or fax machine.
Immediate family means (a) any spouse, parents, and children; (b) any grandchildren, grandparents, brothers and sisters related by blood or marriage; or (c) any person who regularly lives in the other person's household or who regularly lived there within the prior six months.