Piper Jaffray downgraded Career Education (CECO

) to market perform from outperform.

Analyst Mark Maristoca says he downgraded after learning of a grand jury investigation into the company launched by the Dept. of Justice "to determine whether allegations of widespread fraud...merit criminal charges," as reported on the Financial Times Web site.

Maristoca believes shares will likely range-trade in the upper $20s to lower $30s given the news of a grand jury investigation and the potential for additional headline risk. He says he understands Career Education hasn't been advised of a grand jury investigation. Management hasn't confirmed whether a grand jury investigation is even under way.