Of the one thousand-plus serving UK police officers discovered by the Lib Dems to have criminal records, 274 are in the Met. The great majority of these - 235 - are Constables, and one is a Special Constable. Of the rest, 27 are Sergeants, seven are Inspectors, three are Chief Inspectors and one is a Chief Superintendent.
The latter's offence falls into the "traffic" category, which accounts for 251 of the grand total. "Traffic" is inclusive of drink driving violations, but doesn't go into detail.