What Can I Do About Death Threat Against My Daughter? She's 15 & He's The Same Age.

You certainly can do something  about it you can take out a restraining order on him and he cant touch her. You can always call 911 too! Please get help!!!!!

Yes, get a restraining order. If he comes close, he can be put in jail. If he keeps sending more threats, than he can be punished further. Don't believe for a second that you can't do anything.
If it were me, and my child were threatened, I would ask the teachers to mail me her schoolwork and keep her at home until the issue was resolved. If the other kid is serious, I wouldn't give him any chances at all.
Remember, School's work for you. You pay taxes. So feel free to order them to send her work to you. I'm sure her friends would have no problem in visiting her at home if it meant that she was safe.
Please, get help.

While perhaps you cannot talk to that judge, you can certainly contact the courts and have an emergency restraining order granted by another judge.  Also, contact the police personally and advise them of the situation and background.  But DO NOT rely on the police only to protect your daughter-- restraining orders work for law-abiding citizens, and too many people cannot be counted on to abide by the law if they are already so threatening, angry, or just plain hateful.

Practical steps - ask police to help you by contacting parents of the kid to have a clear conversation about situation and repercussions.

Drive your daughter or arrange for her transportation to and from school, and advise counselors and the principal of the situation.

Enlist other parents' support in being present at social events at the school and keeping an eye out on things when you cannot be there.

Ensure your daughter has a working cell phone on her at all times, has your number programmed in, and also knows how to use the 911 feature (which works even if the keypad or phone is locked).

For the time, your daughter needs not to go places alone.  She also needs to avoid being anywhere near this guy as much as possible, avoiding the same hang outs and mutual friends/gatherings.

Advise the DA of the threat immediately, personally or through an attorney.

No, that is ridiculous. You have a threat to your teenage daughter in writing and they won't do anything about until the 14th??? Go right back to the police dept. And get a restraining order immediately. And yes.....charge him with everything and anything you possibly can. A court will not make you wait 3 weeks for a restraining order. Please treat this very seriously. I've seen on the news many times, that the nicest, quietest kids end up shooting up schools and such. Go get a retraining ored now and press charges for the threats. I will pray for your daughter and your family. Even though he got suspended, to many kids that means nothing. If you don't get the restraining order, he might continue to harass her at school or where ever he sees her, even if it's just for a second to call her a nasty name. Please go do it now. Protect your daughter.