Kansas City, Mo. ? A Missouri man prosecutors have called the state’s most prolific serial killer will be tried for 13 homicides at the same time, a judge ruled Thursday.

Lorenzo J. Gilyard, 56, was charged in April 2004 with strangling a dozen women – all but one a prostitute – after a federal grant allowed the police crime lab to begin testing evidence from old, unsolved cases. A 13th murder charge was added in June.

Prosecutors had sought to have the original 12 cases tried in at least two different groups, largely because of logistical problems with assembling more than 160 witnesses. They also had wanted to try the 13th case separately.

“There simply is no logical basis to pluck out certain counts and try them later under these unusual circumstances,” wrote Jackson County Circuit Court Judge John O’Malley. “Although defendant wants a single trial, even if he did not, these matters are best left to the consideration of a single, sequestered jury.”

Gilyard is being held without bond. O’Malley ruled last week to move the trial from October to March 5.

O’Malley also overruled the state’s efforts to prevent the defense from presenting evidence that would cast suspicion on others. Defense attorney Tom Jacquinot said last week that in four cases, there was evidence that others were involved.

More arguments will be heard Sept. 8 on defense efforts to prevent prosecutors from seeking the death penalty. The defense alleges that the sanction would be appropriate because law enforcement destroyed a blue coat recovered from Gilyard’s apartment while investigating the death of Shelia Ingold, 36, who was found dead in an abandoned van in November 1987.

At the time, authorities cut from the coat swatches with blood on them and tested them, but the results did not match Ingold or Gilyard, and Gilyard was eliminated as a suspect. The swatches were put in the crime lab’s freezer, where they remained even after the coat was destroyed in 1998.

When detectives began investigating cold-case files, evidence on the swatches was tested again and matched the DNA profile of Carmeline Hibbs, who was found dead in a parking lot in December 1987. Gilyard is now charged with Hibbs’ death, but had not been a suspect in the slaying at the time.