McHenry County deputy justified in fatal shooting of Nicholas Sebastian: report

The McHenry County state attorney’s office has determined a sheriff’s deputy was justified in fatally shooting a man who fired at him, despite blood tests showing the deputy had "inhalants" in his system.

Deputy Nicholas Arnold fatally shot Nicholas Sebastian, 43, while responding to a report of a man threatening to kill his wife and two children in their home on Jan 11. in Port Barrington, according to a report from the state’s attorney’s office.

Arnold and Deputy Travis Bodway arrived at the scene in the 200 block of Manchester Lane and saw Sebastian "messing with the garage" door before hearing gunshots go off, the report said.

Sebastian’s wife, Antoinette Mecca, began to cry out for help, and deputies found her laying on the side of the garage with a gunshot wound to the leg, the report said.

Sebastian then moved toward Arnold with a gun raised as though he was "going to engage."

Arnold began shooting at Sebastian "until the slide locked back," meaning he had used all the ammunition in his magazine, according to the report.


Sebastian returned fire but did not strike either deputy before falling to the ground. Officials found Sebastian was wearing a bulletproof vest underneath his shirt at the time of the incident. He was pronounced dead on the scene.

Mecca was transported to the hospital and treated for a single gunshot wound. Mecca told authorities that Sebastian had awakened her after an evening of excessive drinking and was acting erratically, eventually throwing her cell phone into a sink full of water.

Earlier, he had also sent texts threatening to kill Mecca and their two children, who were at home at the time, the report said.

When the squad car arrived outside their home, Mecca told deputies she tried to escape by running to the garage, but Sebastian ran after her and began shooting.

Mecca also said when Sebastian saw the squad car out front, he stated, "We’re all going to die."

The couple’s son told investigators Sebastian had been using cocaine and drinking excessively over the past six months and had threatened to kill both Mecca and the children on multiple occasions.

An autopsy found that, at the time of his death, Sebastian had an elevated blood alcohol level and was under the influence of cocaine, opioids and benzodiazepines.

Arnold was also asked to submit to a drug and alcohol test following the shooting, which found "inhalants," in his system.

When abused, the odorless gas found in products like keyboard cleaners can alter one’s mental state.

Toxicologists determined the levels found in Arnold’s blood were most consistent with "intentional use."

Though the state’s attorney’s office was "concerned" by this finding, they determined there was no evidence Arnold was under the influence at the time of the shooting.

The state attorney’s office found Arnold was justified in his use of force, as Sebastian was armed, approaching deputies and verbalizing his intent to harm his wife and children.