ST. LOUIS - A Missouri lawmaker is calling for an investigation of St. Louis County Prosecutor Bob McCulloch, saying he "manipulated" the grand jury in the Ferguson case. McCulloch said in a radio interview on Friday that some witnesses obviously lied to the grand jury.

State Rep. Karla May is pushing for a state investigation, saying she believes McCulloch helped sway the grand jury into the decision not to indict Ferguson Police Officer Darren Wilson in the shooting death of 18-year-old Michael Brown, who was black and unarmed.

McCulloch, who convened the grand jury in August, was interviewed Friday by KTRS Radio in St. Louis. It was his first interview since he announced the grand jury decision on Nov. 24.

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

He 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 did not return messages left with his office on Friday seeking comment about May's allegations, and whether he would pursue perjury charges against any witnesses who may have lied.

The shooting by a white police officer on Aug. 9 spurred significant unrest, both in August and immediately after the grand jury decision was announced. Twelve Ferguson-area businesses, along with police cars, were burned on Nov. 24, and several other businesses were damaged.

In the radio interview, McCulloch also defended the decision to make the announcement at night, saying it was best for schools and allowed business owners time to decide whether to open the next day.

A joint House and Senate committee is already investigating why 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.