A former church secretary has pleaded guilty to murder charges in the 1983 slaying of her husband and admitted that she gave her former minister the handgun used to kill him. The alleged love triangle formed the basis of a television miniseries. Lorna Anderson Eldridge, 35, entered the plea to second-degree murder Thursday, telling the court that she and Thomas Bird plotted the 1983 slaying of Martin K. Anderson. Mrs. Eldridge said she and Bird hatched a plot in which she stopped her van on a rural highway and pretended to lose her keys so that her husband had to get out and look for them. The Lutheran pastor then shot her husband, she said. The slaying and Mrs. Eldridge's reputed love affair with Bird were dramatized in the CBS miniseries ``Murder Ordained'' in 1987. Mrs. Eldridge and Bird, 38, already are serving prison terms. She pleaded guilty in 1985 to criminal solicitation in an earlier, unsuccessful plot on her husband's life and was sentenced to five to 18 years. Bird, who has not been charged in Anderson's death, was convicted in 1984 of criminal solicitation in the unsuccessful plot. He was sentenced to two-and-a-half to seven years in that case, and to life in prison for murdering his wife, Sandra, in 1983. Sheriff Bill Deppish said Mrs. Eldridge's statement was an ``important breakthrough'' that could lead to new charges against Bird. Mrs. Eldridge, who remarried, originally was charged with first-degree murder but accepted a plea bargain under which the prosecution will seek a 10-year prison term at sentencing Jan. 3. Second-degree murder carries a maximum penalty of 20 years to life in prison. Jack Focht, Mrs. Eldridge's attorney, called the case ``kind of the great American tragedy _ that people romantically come apart sometimes and get involved romantically and violence sometimes happens. ``And when it happens as it did on Nov. 4, 1983, lives get stamped indelibly, lots of lives,'' he said.