Investigators believe that the man charged with the attempted assassination of President Donald Trump shot a Secret Service officer who was wearing a ballistic vest, according to three law enforcement officials familiar with the case.

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Investigators have determined that the Secret Service Uniformed Division officer was not struck by friendly fire from another member of law enforcement, the sources told NBC News on Wednesday.

Cole Tomas Allen, 31, on Saturday allegedly charged a checkpoint one floor above the Washington Hilton ballroom where the president was attending a black-tie event for the White House Correspondents’ Association.

Cole was caught on video running with a shotgun and other weapons. Officials say an officer was hit on his vest and returned fire.

The officer was taken to a hosptial but released over the weekend.

Allen was charged with discharging a weapon but has not been formally accused of assaulting a federal officer.

A law enforcement source said work continues analyzing Allen’s devices including desktop and laptop computers from his California home as well as his phone, laptop and hard drives recovered from his guest room at the Washington Hilton hotel.

Allen, a teacher and engineer from Torrance, California, made his first court appearance Monday and was charged with the attempted assassination of the president, interstate transportation of a firearm and ammunition with intent to commit a felony and discharge of a firearm during a violent crime.

Selfies that Allen took in his hotel room on Saturday night before the attack were included in a filing from prosecutors Wednesday. The photos showed him standing in front of his hotel room mirror wearing black and a red necktie.

According to the filing, the image showed the suspect “wearing a small leather bag consistent in appearance with the ammunition-filled bag later recovered from his person,” along with a shoulder holster, a sheathed knife, pliers and wire cutters.