Killer Instinct 1 and 2 should be working in MAME 2003 but there is a bug that currently prevents it. There is now a bounty open to raise the funds to attract a coder to fix this bug.
@juhapik Thanks for the attention, but it always worked and this questioning was before installing the first unstable version made available through update 4.0.1, these doubts were resolved 2 months ago