Jeffrey L. Dahmer on Monday pleaded guilty but insane to the slayings of 15 young men and boys.
If found insane, Dahmer could be sentenced to a mental institution where, after a year of treatment, he could petition for release every six months.
However, defense attorney Gerald Boyle and Dist. Atty. E. Michael McCann said the chances are slim that Dahmer would ever be released.
Six months ago, Dahmer admitted killing and dismembering 17 young males, having sex with some of the corpses and saving one victim's heart to eat.
But at least two relatives of his victims believe that he is sane.
"His plea is horrible," said Shirley Hughes, mother of victim Anthony Hughes. "It's driving me mad. He's not insane."
"Jeffrey Dahmer knows what he's doing," Carolyn Smith, sister of victim Eddie Smith, said later. "He's insulting our intelligence by saying he was insane. . . . All of us want him to go to prison and take his justice like a man."
Dahmer, 31, a former chocolate factory worker, was only charged with two counts of first-degree murder and 13 counts of first-degree intentional homicide because the first slaying took place in Dahmer's hometown of Bath, Ohio, in 1978, and prosecutors said there was not enough evidence on one slaying Dahmer claimed in the Milwaukee area.
He has been charged in Ohio and will stand trial there after sentencing here.
By pleading guilty, Dahmer avoids the initial phase of the trial, held to determine guilt, and moves directly to a second phase, where his sanity will be judged.
If judged sane, Dahmer would receive a mandatory life prison sentence. Wisconsin has no death penalty.