Nobody in the family recognized where the toy donkey was sitting. It was on the couch in the house of a murdered Milwaukee woman in 1988, and when a relative arrived she told the detective it did not belong there; its place was on a chair, the chair where the body had been found. The detective turned it over and saw fresh smears of blood. At the Wisconsin State Crime Laboratory, analysts established that the blood was not the victim's. Because it was fresh, investigators concluded it was the killer's.
At that point there was no suspect at all. Elderly women were being killed in their homes across the city at a rate the prosecutor later put at about one a week, and burglaries in the same districts showed the same method of entry and the same way of turning the rooms over. A University of Wisconsin yearbook's review of 1988 and 1989 recorded that the murders of five elderly people in their Milwaukee homes that January had spread fear through the city, and that no one had yet been charged. The published record does not establish how many of those five were among the deaths later laid at Robert Wirth's door.
The cause of death was established by autopsy rather than assumed. Three medical examiners reviewed all the protocols and concluded that one man was responsible for three of the homicides. Each woman had suffered a complete avulsion of the voice box, and the examiners believed the necks had been stamped on. They died of asphyxiation, and the internal and external injuries were distinctive enough for all three examiners to attribute the deaths to the same person.
That finding shaped the prosecution's plan. If they could find the assailant and build a full genetic profile for a single victim, the reasoning went, the medical examiners' testimony would carry the case for all three homicides together.
Months later a man tried to rob a Milwaukee taxi driver. The driver fought him and took his gun away, and when police traced the weapon they found it had been stolen from a house next door to one of the dead women. The man was Robert Wirth, born in 1960.
Investigators obtained his blood through a John Doe proceeding and set about matching it to the blood on the toy, at a time when DNA testing was far from routine. Conventional ABO and enzyme markers gave a figure of one in 4,565. A DQ alpha test, then the only PCR marker available, was run in California and matched. Gamma and kappa markers were run in Minneapolis. Further work produced four RFLP markers, and the most conservative combined figure put the match at one in 800,000. The prosecutor said afterward that in that era a figure of one in a thousand was considered a terrific case, and that he doubted the earlier numbers alone would have satisfied a jury, since the blood was the only physical evidence they had.
The burglaries went before the jury as other-acts evidence, the method of entry and the ransacking being almost identical to the homicide scenes. The trial lasted six weeks with the jury sequestered, and the conviction rested largely on the genetic evidence. In 1991 Wirth was sentenced to four consecutive life terms plus twenty years.
The count does not reconcile cleanly. The prosecution described three homicides tried together, yet the recorded sentence is four life terms, and nothing published explains the fourth. Reference works put his total at six to eight without identifying the others. Of the women whose deaths went to trial, only one is named in the prosecutor's own account, given in a presentation on DNA evidence published in 2000: Mrs. Bresnahan, whose house held the toy donkey.
1960: Robert Wirth is born.
1988: in the house of a murdered Milwaukee woman, Mrs. Bresnahan, a detective finds fresh blood on a toy donkey that turns out not to be the victim's.
1991: after a six-week trial resting largely on the genetic evidence, Wirth is sentenced to four consecutive life terms plus twenty years.