ST. LOUIS — St. Louis Circuit Attorney Kim Gardner, understaffed and facing criticism for tumult in her office, has hired at least five new staffers, including a former assistant attorney general to serve as her chief trial assistant.

The new hires include three starting attorneys, each making $50,000 a year, a secretary in the diversion program, at $40,000, and Marvin Teer, chief trial assistant, who will make $120,000 annually.

Gardner won election twice promising to revolutionize prosecution in St. Louis. But she has struggled to keep staff and manage cases. In September, a Post-Dispatch story highlighted dozens of departures that left the office without key leaders and with far fewer experienced trial lawyers, leading to unprepared attorneys, dismissed cases and biting criticism from police, defense lawyers and victims.

Teer, 59, has been on the job for just over a month. Gardner called Teer this summer to invite him to come out of retirement, he said.

“I love trying cases,” he said.

Teer will be responsible for managing trial attorneys, caseloads and, in part, the office in general. He will train prosecutors — an “amazing, young team of lawyers who are doing what needs to be done.” And he will also try cases himself — he’s already working on roughly a dozen, right now.