Citi analyst Jonathan Raviv sees "more questions than answers" after Booz Allen Hamilton disclosed a Department of Justice civil and criminal investigation relating to elements of the company's cost accounting and indirect cost charging practices. A share selloff is warranted as the disclosure "takes some shine off, especially for a stock that has typically traded at a premium," Raviv tells investors in a research note. He notes that an 8% yield to his FY19 free cash flow per share estimate yields a $28 stock. The analyst has a Neutral rating on Booz Allen with a $41 price target. The stock in premarket trading is down 16%, or $6.23, to $33.10.