Over the last three decades Ren-Yuan Zhu and his colleagues have been involved in the successful development of scintillating crystals for precision crystal electromagnetic calorimeters in high energy physics, such as the L3 BGO, BaBar CsI(Tl) and CMS PWO. Several Advanced Detector Research awards and Collider Detector Research and Development awards were received from the DOE Science Office for the development of PWO, LSO/LYSO and other cost-effective crystals for future HEP experiments at the energy and intensity frontiers. In 2009, Ren-Yuan Zhu established a program for crystal development in the Caltech HEP program. The main goal of this program is to develop inorganic scintillator-based novel detector concepts for future HEP experiments, such as an LSO/LYSO crystal-based total absorption and sampling calorimeter concept, a barium fluoride crystal-based very fast crystal calorimeter concept, and a cost-effective inorganic scintillator-based homogeneous hadronic calorimeter concept. Recent emphasis of this program is devoted to the development of ultrafast inorganic scintillators, such as the yttrium doped barium fluoride crystals featured with a sub-ns FWHM pulse width, a significantly suppressed slow scintillation component and an excellent radiation hardness. Also under development is LuAG ceramics with excellent radiation hardness and other cost-effective inorganic scintillators. This work is supported by the U.S. Department of Energy, Office of High Energy Physics program under Award Number DE-SC0011925.