KSDK-TV, St. Louis

ST. LOUIS — Some witnesses who testified before the grand jury that investigated the shooting of an unarmed teenager clearly lied under oath, according to St. Louis County Prosecutor Bob McCulloch.

In an interview Friday with radio station KTRS in St. Louis, McCulloch said he had no regrets about letting the grand jury hear from non-credible witnesses.

"Early on I decided that anyone who claimed to have witnessed anything would be presented to the grand jury," said McCulloch, who convened the grand jury in August.

"Clearly some were not telling the truth," he said.

It was McCulloch's first interview since he announced on Nov. 24 that the grand jury would not indict Ferguson police Officer Darren Wilson in the shooting of Michael Brown, an 18-year-old black man who was unarmed.

McCulloch made reference to one woman who claimed to have seen the shooting. McCulloch said she "clearly wasn't present. She recounted a story right out of the newspaper" that backed up Wilson's version of events, he said.

McCulloch said he's not planning to pursue charges against witnesses who lied.

The shooting by a white police officer on Aug. 9 spurred significant unrest, both in August and immediately after the decision not to indict was announced. Twelve Ferguson-area businesses, along with police cars, were burned on Nov. 24, and several other businesses were damaged.

Meanwhile, state Rep. Karla May is calling or a state investigation of McCulloch, saying he "manipulated" the grand jury into the decision.

A joint House and Senate committee is already investigating why Missouri Gov. Jay Nixon did not use National Guard troops in Ferguson on Nov. 24. May, a St. Louis Democrat, sent a letter Thursday to committee chairman Sen. Kurt Schaefer, urging that the investigation expand to look at whether McCulloch committed prosecutorial misconduct.

Contributing: The Associated Press