The United States Secret Service has acknowledged a series of security failures it made during a July campaign rally where Republican presidential candidate Donald Trump was shot at and wounded in the ear.

In a review of the July 13 assassination attempt in Butler, Pennsylvania, the Secret Service identified “deficiencies” in advanced security planning and poor coordination with local police, said the agency’s acting director, Ronald Rowe.

“While some members of the advance team were very diligent, there was complacency on the part of others that led to a breach of security protocols,” Rowe told a news briefing on Friday.

Questions over the competency of the elite US law enforcement agency have swirled since a gunman perched on a rooftop opened fire at Trump during the rally, grazing the former president in the ear and hitting three people in the crowd, one fatally.

Congressional officials lambasted the agency for failing to clear the area or respond quickly to the attacker, who local officers were alerted to up to 20 minutes before the shooting.

• Read More