The Boston Police Department helped cover up for Detective Robert Tully when he drunkenly crashed his department car in Rockland in 2013 and hurt a nurse so badly she spent four days in the ICU, according to a Globe investigation published last month.

Now, new documents obtained by the Globe show it was not the first time police stepped in to protect Tully. MBTA Transit Police and Boston police covered up his alleged drunk driving in a department vehicle four years earlier.

Tully faced no sobriety test. No criminal charges. No internal affairs investigation. And documents related to the case were sealed by Transit police.