A private security officer who shot a pet dog in the head in front of its owner at Honolulu Airport Tuesday night is being investigated for reckless endangering in the second degree and was previously fired as a civilian police officer for the Army “for pulling a gun too much,” according to state Sen. Will Espero.

Espero, the former chairman of the Senate’s Public Safety Committee, said a high-ranking sheriff’s deputy based at the Sheriff’s Department’s airport sub-station told him that the unidentified “older … airport police” officer previously provided Department of Defense security as a civilian at Fort Shafter and possibly Fort DeRussy but was fired, although the date is unclear.

The state Department of Public Safety, which oversees the Sheriff’s Department, said in a statement that “there is an active investigation into Tuesday’s incident at the airport being conducted by the state Sheriffs. It would be premature to release findings until the investigation is complete.”

The sheriff’s deputy told Espero that Securitas Security Serv­ices USA, which provides security at the airport, hired the man even though the Defense Department had fired him for “pulling a gun too much and a variety of other things.”

The deputy later told Espero that the man also had been “over-bearing. … He should never have been picked up by Securitas because he has a history,” the deputy told Espero. “This time he proved it. He shot something,” the deputy said.

Securitas’ director of security, former Honolulu Police Chief Lee Donohue, said the shooting is under investigation and he had no comment.

There have been frictions between Securitas’ armed “airport police” and sheriff’s deputies at the airport. The deputies’ union, the Hawaii Government Employees Association, filed a lawsuit last year challenging Securitas’ security contract at the airport.

Leisha Ramos told the Honolulu Star-Advertiser that the security guard shot her 2-year-old, pit-bull mix dog, Kai‘ele, after they arrived on separate flights from Hawaii island.

Ramos said her boyfriend picked up Kai‘ele at the air cargo area, then drove his truck and parked near a grassy area just mauka of the Hawaiian Airlines terminal.

Kai‘ele was left chained to a nearby coconut tree, and Ramos said her boyfriend went to gather her luggage at the baggage claim area.

Ramos said a security officer parked his truck, got out of his vehicle, and was shouting at her and her boyfriend that they had to leave and remove the dog from the area. She said he shouted at them and pulled out his weapon.

“My dog stood up. … He was wagging his tail,” she said.

She said Kai‘ele’s chain broke but she immediately grabbed his collar before the dog pulled away.

Ramos said she was holding her 5-month-old baby when the guard shot the dog in the forehead from a few feet away.

She said the security officer’s behavior aggravated the situation.