I cannot tell from this photo what is wrong with this juniper. It could be Phomopsis tip blight, or another pest. I highly suggest you send a sample to Brian H. Junipers did not break dormancy early and so were not harmed by the April frosts so I would rule this out. It would help to know what cultivar/species of juniper this is as some are quite susceptible to disease.
I agree with Laura that a sample to the clinic is in order. There are several canker organisms (Phomopsis being a major player) that might cause dieback of this type.