Updated 12/30/13 – 11:36 a.m.

CHICAGO (CBS) — The sheriff’s office says a 17-year-old who was in Cook County Jail on an armed robbery charge has committed suicide in his cell at 26th and California.

Tyshawn Carter was charged as an adult with armed robbery, and Cook County Sheriff’s office spokeswoman Cara Smith said the 17-year-old had been in the jail for a month.

Smith said the young man — whose name has not yet been released — hanged himself with a bedsheet in his cell, and that he was in the cell by himself.

“Suicides is something that we are keenly aware of and we work very diligently to minimize the risks that all the detainees in our custody face,” Smith said. “Holidays are a tough time of year, so we are very aware of the issues that our population faces. And we’ll be reviewing the facts and circumstances in the case, as we do all others.”

Smith said there was a suicide in the same medium-security jail division – Division 10 – three weeks ago.

The suicide is being investigated, including Carter’s cell placement, according to Smith.

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