>What is halter? Do you mean he wanted to win in 4 categories on the same Olympic games or he tried in 4 different olympics?

It seem you don't know about halter. :)
Anyone cannot win even two different categories with halter at olympics. Because only one golden medal giving per weight halter at olympics.

of course different 4 olympics...

2004 - fail with zero weight.
2000 - won
1996 - won
1992 - won (under Bulgaria citizenship)