Starter Issues?

My father's 1992 Olds 88 just developed a starting problem. It doesn't happen every time, but I witnessed it today.

When you crank the engine, it does turn over, but in a "jerky" fashion. The starter is starting and stopping so fast that it sounds like a machine gun. While cranking, the lights inside the car flicker. Is this a mechanical problem originating in the starter, causing it to draw too much current, or is it electrical in root cause?

Try cleaning the battery cables,that is first removing the neg.cable then the both pos. cables and seperate and clean clean them good (one cable goes to the starter and the other to all the other circuits ) also check to see if by chance the starter or cables are loose,coat the cables with dielectric grease and reinstall (positive first) then test again and post back and let us know what's going on. good luck

Well, my father replaced the starter itself this week. Seems OK now. I'll post again if there are any more issues.