Even as the investigation and manhunt were underway, officials faced a groundswell of concern across the Jewish community, where early speculation included al Qaeda-inspired terror as a motive.
Instead, officials believe, Hirsch, a transient with an alias and a grudge that may be seated in a personal relationship at one religious institution was the one officials believe triggered a Friday afternoon security alert by the Anti-Defamation League to synagogues and other Jewish organizations in the Los Angeles area.
Hirsch also is known as Israel Fisher, according to information released by police. He constructed the projectile device using elements including concrete, explosive powder, dry ice and what appears to be an expansion joint sealant, or other expanding plastic or foam.
The oddly constructed mechanical launcher appears to have been highly effective at hurling its material, although it did not seriously damage the Chabad House which appears to have been its target.
According to the Santa Monica Police Department, Hirsch, a heavyset white male was being sought on state charges of possession of a destructive device and unrelated local charges. He was "known to frequent synagogues and Jewish community centers seeking charity from patrons," one police official said. He was known to stay in motels from time to time for a night at a time.
ABC News' Howard Price contributed to this report.