California residents who lit illegal fireworks over the July 4 holiday may be in for a nasty surprise in the mail thanks to covert fire department operations.

Homeowner Earl Decastro, 46, was nabbed and booked for involuntary manslaughter, though he has since posted his $25,000 bail.

Charges are pending Monday against a Buena Park homeowner who allegedly operated an illegal Fourth of July fireworks display that misfired, killing an 8-year-old girl. The homeowner remains under arrest as the Orange County District Attorney’s Office reviews the mishap that resulted in the death of Jasmine Nguyen of Anaheim.