A woman arrested for allegedly driving while under the influence of alcohol was able to enter the Travis County jail with a deadly weapon concealed in her bra. The Austin Police Department said the weapon was missed during a pat down at the detainment site, and now the incident is under investigation.

It's the second case in six months involving a detained person having a lethal weapon in his or her possession.

Austin police said the most recent incident occurred on May 29 around 6:30 a.m. As the woman was being processed in central booking, a female corrections officer began a routine pat down. The corrections officer said she found a loaded gun inside the woman's bra.

The gun was given to the arresting officers to process and jail officials notified Austin police.

"We have training and protocols to address the appropriate techniques of frisking and searching suspects. The dangers posed by missing a weapon on a suspect cannot be overstated," said Interim Chief Brian Manley.

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In January, a 19-year-old man shot himself to death in the back of an Austin police patrol car after being charged with shoplifting. The arresting officers in that incident said they did not properly search him because he had already been cuffed by an employee associated with Macy's.

An internal affairs investigation, in that case, remains open.

Chief Manley said immediately after the May incident, patrol supervisors reminded officers -- once again -- about the proper pat down procedures. He says the department will also issue a bulletin to officers in the next few days.

From 2013 through 2016, an estimated 200,000 people were processed in the Travis County Jail. In those years, officers discovered one gun, one stun gun, 40 knives and four razor blades.