a memorial patch for four slain officers from the oakland police department

on march 21, 2009, four oakland police officers were shot and killed by a parolee for whom a no-bail warrant had been issued.  the a's paid tribute to the fallen officers by wearing an 'opd' patch on the right sleeves of their home white jerseys.  the patch is visible on landon powell's sleeve (and you can kind of see it on mike gallego's as well) on powell's 2010 topps card

as well as vin mazzaro's 2010 topps card

topps must have used a photo from 2009 on brett anderson's 2011 topps card because the patch is visible

just as it is on adam kennedy's 2010 upper deck card

i like kennedy's card, but the card in the binder for this memorial is daric barton's 2010 topps card

it gives the best look at the patch.

the four officers, sergeant ervin romans, sergeant mark dunakin, sergeant daniel sakai, and officer john hege, had sometimes worked security at a's games, and the team also held a fundraiser, raising $130,000 for their families.