An Arkansas gun dealer is to testify today in Oklahoma in the state murder trial of bombing conspirator Terry Nichols. Roger Moore is expected to testify about a home-invasion robbery in November 1994 at his home in Hot Springs, Arkansas. Prosecutors say Nichols took part in the robbery and that the stolen weapons were sold to finance the Oklahoma City bombing. Meanwhile, Judge Steven Taylor is expected to rule tomorrow on a defense motion to dismiss the case. Defense attorneys say prosecutors have withheld evidence crucial to Nichols` defense. Nichols faces 161 state murder charges and prosecutors are seeking the death penalty.