According to the Attorney’s Office of the Eastern District of California, Cebula had made threats from July 2 - July 3. 

The FBI lead investigation found that his threats also mentioned the usage of other dangerous weapons. Given the severity of the threats and the potential danger they pose on both staff and civilians, he was promptly arrested a week later.

It is currently unknown as to what triggered Cebula to threaten the company originally. 

If found guilty, he can face a maximum sentence of 5 years and a fine of 250,000.