The Prince George’s County councilwoman was back on the job Monday, doing council business three days after she turned over her county-issued property — including her laptop, cell phone, and vehicle — on council instruction. Johnson pleaded guilty June 30 to charges of conspiring to commit federal witness and evidence tampering, admitting to stuffing $79,600 in cash in her bra and underwear and flushing a $100,000 check down the toilet at the instruction of her husband, then-County Executive Jack Johnson. She plans to resign on July 31.