He completed training at the Senior Management Institute for Police and graduated from the FBI National Academy, 145th Session in June 1986.

His tenure as director was called "relatively free of trouble, at least by local standards" by the Miami New Times, although in 2004 a group of policemen who served in the department described his management style as marked by "favoritism and retaliation".

[8] In 2009, Alvarez led a successful yet controversial effort to spend hundreds of millions of dollars of the city's money to build what would eventually be LoanDepot Park on the site of the Orange Bowl to retain the Major League Baseball Marlins in the region.

In August 2009, The Miami Herald revealed that Alvarez had recently given pay raises to close aides, including his chief of staff Dennis Morales, whose new salary was over $200,000 a year.

[7] An effort to recall Alvarez began in October 2010, backed by billionaire businessman Norman Braman, a former owner of the Philadelphia Eagles, over Alvarez's simultaneous tax increases and pay raises for upper echelon county workers.

In January 2013, he emerged from relative seclusion to compete in the National Physique Committee's South Florida “Over 60s” Master's bodybuilding competition, where he won first place.