1997 Chevy Lumina starting problems

Over the last 3 days or so my Lumina has been starting slower and slower, as in it turns over at a slower rpm when the starter is engaged. The last time it barely rolled over once and will no longer turn over. I removed the battery and had it checked, all was well with it, it was holding a charge and all the cranking amps it needed etc. Would a bad starter explain the slow decrease in starting performance over a 3-4 day period?