HOUSTON, Texas (CBSDFW.COM) – A Houston police officer who is under criminal investigation for allegedly participating in the Jan. 6 riot at the U.S. Capitol and going into the building has resigned from the department, the chief announced Thursday.

The Houston Police Department is currently performing a joint investigation with the FBI and Department of Justice on the officer, who has not yet been identified.

During a news conference Wednesday, Houston Police Chief Art Acevedo confirmed the investigation after he said he received a tip on Sunday.

The assault on the U.S. Capitol building happened after President Donald Trump and his supporters called for the 2020 election results to be overturned due to unfounded claims of voter fraud. In the end, five people, including Capitol police officer Brian Sicknick, died as a result of the Capitol siege. One person, Air Force veteran Ashli Babbitt, was shot to death by an officer as she was breaking into the building and three others died from medical emergencies, according to police.

“On Sunday I received information from an individual that one of my officers might have been in D.C. for the protest and may have participated on the attack on the Capitol… I immediately contacted the FBI…” Acevedo said. “We launched a joint investigation Sunday afternoon. I can tell you that this morning a member of the Houston Police Department has been determined that on his own time to have not only attended a rally, which is their First Amendment right, but this individual has been determined to actually have been penetrated the Capitol and that person has been placed on administrative leave.”

After the officer was placed on leave, the chief announced the officer “tendered his resignation” Thursday morning. KTRK reports the officer is believed to be an 18-year veteran of the department.

Acevedo on Wednesday also voiced his frustration about a police officer allegedly participating in the Capitol riot.

“There is no excuse for criminal activity, especially from a police officer. I can’t tell you the anger I feel at the thought of a police officer, and other police officers, thinking they get to storm the Capitol,” Acevedo said.

Acevedo said there is a “high probability” that the officer faces federal charges.

On Wednesday, two Midland, Texas residents, Jenny Cudd and Eliel Rosa, were arrested for their alleged involvement in the riot. On Sunday, Larry Brock of Grapevine was also arrested after he was allegedly seen inside the Senate Chamber holding zip ties.

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CBSDFW.com Staff