Further investigation on the case of David Dao, the United Airlines passenger violently dragged out of an overbooked flight by airline officers, reveals the passenger to have reacted violently against flight crew members before authorities had him removed from his seat. Aviation police investigations cleared United Airlines of the stigma associated with videos of the incident leaked online.

According to USA Today, the Kentucky-based doctor was "violently flailing his arms" and was "verbally abusive" to the crew before airline crews have called on authorities to physically remove the man from the flight. Officer James Long, one of the officers who attempted to remove Dao from his seat, said the doctor had knocked his arm causing the doctor to "fall, hit and injure his mouth on the armrest."

Officer Mauricio Rodriguez Jr. said that Officer Long had only used "minimal but necessary force" when he tried to remove Dao from his seat. Two other officers, Steven Smith and Sergeant John Moore also gave their statements with Smith saying his statement is given "under duress" as he could lose his job if he refused to say anything about his actions in the incident. All four officers are on administrative leave after the incident.

Aside from Aviation Commissioner Ginger Evans investigating the case, Chicago Inspector General Joe Ferguson had also launched an inquiry to the infamous incident that sparked international furor against the airline and its treatment of passengers. However, Ferguson's investigation's focus might be as different from Evans' initial investigation and further clarification is unavailable as Chicago Sun Times stated both Ferguson and Evans could not be reached for comment on the matter.

Chicago Mayor Rahm Emanuel also did not elaborate on Ferguson's investigation. He only said that the Inspector General is conducting an investigation because the actions of United Airlines and the outcome for Dao were "totally unacceptable." The outcomes of both investigations could steer the fate of the 292 aviation police officers for their usefulness in airports.