A truck painter pleaded guilty on Wednesday to strangling 48 drug addicts and prostitutes to death ? in a killing spree known as the Green River murders ? and said in a confession, ?I killed so many women, I have a hard time keeping them straight.?

Gary Leon Ridgway, 54, said in a confession read by a prosecutor in open court that he murdered the women because he hated prostitutes and knew that they would not be missed. As details of his grisly crimes unfolded, relatives of the victims wept in court and the owlish-looking Ridgway showed no emotion.

Ridgway, who some law enforcement officials believe may have killed more than 100 women, pleaded guilty in return for prosecutors' agreement to spare his life. His confession included details of how he gained his victims? confidence by showing them pictures of his son, had sex with them and then took pleasure in strangling them from behind, often in his house or truck.

?I hate most prostitutes?

Dressed in red prison garb, Ridgway confirmed through questioning with prosecutor Jeff Baird that he murdered 48 women, mostly prostitutes, in a killing spree that started in 1982. Relatives of his victims broke down sobbing in the courtroom, some hurrying to exit with tears streaming down their reddened faces.

The 48 convictions are the most for any serial killer in US history and the case is the nation's longest-running serial killer probe. While always a prime suspect, Ridgway eluded arrest until DNA evidence tied him to several of the murders.

In his confession read to the court, Ridgway said, ?I picked prostitutes as my victims because I hate most prostitutes and did not want to pay them for sex. I chose prostitutes because I knew they would not be reported missing right away .... I picked prostitutes because I found I could kill as many of them as I wanted without being caught.?

Defense attorney Anthony Savage said his client was ?consumed with rage? but even Ridgway could not say why, likening his own behavior to alcohol or drug addiction. ?Something is clearly out of whack?, Savage told reporters. ?He says he's sorry. I believe him, but how do you really know ??

Chris Stetkiewicz