SACRAMENTO (CBS13) – An inmate at the Sacramento County Main Jail was released from custody after testing positive for the coronavirus, CBS13 confirmed after obtaining an internal email sent to a defense attorney from a federal prosecutor.

This is the first occurrence of an inmate at the jail testing positive for COVID-19.

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The Sacramento County Sheriff’s Department said it was a female inmate who tested positive and was released Wednesday night.

Officials are now scrambling to retrace her steps.

“We are going back with the help of county health and correctional health services to identify any potential contacts she had,” said Sgt. Tess Deterding, with the Sacramento County Sheriff’s Department.

Deterding said that one of the two women’s floors in the facility is on lockdown after the diagnosis was learned.

The sheriff’s office said this particular inmate, whose identity has not been released, was arrested six days ago, was asymptomatic but tested anyway. Six days into her seven-day isolation, the test came back positive and she was immediately released from custody.

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The sheriff’s department said they believe the woman contracted the virus prior to entering the facility. Deterding said no other inmates were exposed.

The protocol for inmates who do enter the jail is that they are immediately put into seven-day isolation and monitored for symptoms of COVID-19.

Since the outbreak, the jail has released 1,100 inmates by order of the courts – an order to help prevent the spread of the coronavirus inside jail populations.

“We do have the space and we do have the ability to isolate for seven days,” Deterding said.

But some deputies inside the jail told CBS13 they are concerned for their own safety.

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Julie Prayter, with the Sacramento County Deputy’s Sheriffs’ Association, said in part, “according to SCDSA President, Kevin Mickelson, no unsafe circumstances were found.”