AUSTIN – A convicted burglar slipped out of his prison unit to buy cigarettes, then returned unnoticed a short time later, authorities said, eventually leading to a contraband search and further criticism of Texas prison security.

"It might be funny if it weren't so absurd," said state Sen. John Whitmire, D-Houston, chairman of a committee that oversees the prison system. "People shopping at a Walmart shouldn't have to worry that the person standing next to them in line is supposed to be in a prison."

Policies regarding trusties and how they are supervised are being reviewed, prison system spokeswoman Michelle Lyons said.

Authorities at the Central Unit in Sugar Land used security video from a Walmart to confirm that Skyler Steddum, 19, was at the store. Steddum returned unnoticed to the fenceless trusty unit, the Austin American-Statesman reported Tuesday.

The Central Unit is now undergoing a search for contraband, including cigarettes, prison officials say.

Its camp, outside the main prison yard, houses about 300 minimum-security convicts.

John Moriarty, inspector general for the Department of Criminal Justice, says Steddum slipped out on Feb. 23. Investigators did not learn of his quick trip, allegedly one of dozens made by Steddum in recent months, until Friday night when another inmate snitched on him.

"He bought smokeless tobacco and cigarettes. I don't know how much," Moriarity said.

Steddum is serving four years for home burglary and unauthorized use of a motor vehicle in Nueces County.

It was the latest security breach in Texas prisons since officials promised improved security in late 2008, after a death row convict used a smuggled cellphone to make threatening calls to Whitmire.

"The fact that Walmart has better security cameras than our prisons, well, this whole situation begs a whole lot of questions," the senator said.