Robert S. Treff, the former Internal Revenue Service employee who killed his wife at Christmas 1986, is competent to stand trial on charges he tried to kill the IRS district director with a fire-bomb.

That was the ruling Tuesday by U.S. District Judge Juan Burciaga of New Mexico, presiding in the case. The decision supersedes an incompetency finding by Bruce S. Jenkins, chief judge of the U.S. District Court in Utah.Treff, who lived in Provo, is serving a term of one to 15 years in the Utah State Prison for shooting his wife, Jennifer. He was indicted by a federal grand jury on charges of assault, intimidation, possession of an unregistered firearm and illegal use of a firearm in an alleged attempt to kill IRS District Director Carol Fay on the same day as the murder.

In March, Jenkins ruled that a mental disability - a hyperactivity problem - prevented Treff from helping in his defense.

But since then, Treff was sent for further examination at the federal facility in Springfield, Ill., where doctors determined he is now competent to stand trial.

Meanwhile, Treff filed a motion asking the judges in Utah to recuse themselves from the case because they know Fay. Jenkins asked that a judge from another state be appointed, and Burciaga took the case.