Michael Mann and Johnny Depp will make “Public Enemies” for Universal. Meeting hours before the Hollywood premiere of Depp’s “Sweeney Todd,” the director and actor shook hands on a deal that triggers a March 10 start for “Public Enemies” in Chicago. Drama is set during the great crime wave of 1933-34, when the government’s attempts to stop Depression-era criminal legends such as John Dillilnger, Baby Face Nelson and Pretty Boy Floyd transformed J. Edgar Hoover’s FBI into the country’s first federal police force. Mann wrote the script, based on Bryan Burrough’s 2004 book. Depp will play John Dillinger, considered the most notorious gangster of the era.