Thomas Kaiser, 60, and son Erich Kaiser, 29, plead guilty to firing off a signal cannon in a Manville park on July 6 that severely injured a bystander.
An explosion in a Manville park during a party on July 6 sent shrapnel flying 75 feet into his abdomen that led to 10 surgeries in three weeks and he's not done.
Thomas Kaiser, charged in connection with the explosion of a device in a Manville park, discarded explosives at his South Plainfield home in 2019 which led to the cancellation of the Labor Day parade.
Police said a signal cannon, a device designed to create a large boom and smoke when lit, sent shrapnel into several vehicles and homes near a Manville park.
Surveillance video of the explosion obtained by CBS New York shows someone lighting the device inside Cooper Street Park in Manville and then run away just before it went off.