Mount Vernon Mayor Richard Thomas has fired his public safety commissioner, but the reason for the firing is unclear.

Bob Kelly was sworn in to the position in January, becoming the city's first public safety commissioner. At the time, Thomas praised Kelly, calling him a "very well-respected law enforcement professional."

Thomas fired Kelly this past weekend, saying the firing was a business decision. "Things often start off with the most sincere of intentions, but it didn't work out," said Thomas. "It is a personnel matter." He also said he won't debate his rationale for the firing.

Kelly hasn't commented on his firing.

Thomas wooed Kelly to the position -- and even wanted him to be named as deputy mayor, which is a position that didn't exist in the city charter. 

Kelly has a long and distinguished resume. He spent more than 20 years with the Mount Vernon Police Department before he retired as a captain. He went on to work for the Westchester County District Attorney's Office, where he created the county's intelligence center. 

Deputy Public Safety Commissioner Ronald Fatigate is now the acting commissioner, and a search is underway to fill the position permanently.