Blair, 46, is charged with six counts of first-degree murder in the 2004 deaths of six women: Sheliah McKinzie, 38; Patricia Wilson Butler, 45; Darci I. Williams, 25; Anna Ewing, 42; Carmen Hunt, 40; and Claudette Juniel, 31.
Their bodies or remains were found in 2004. Two of the women had been strangled, but the causes of death of the other women could not be determined because their bodies had decomposed so badly.
Charges against Blair in two other slayings — those of Nellia Harris, 33, and Sandra Reed, 47 — were dismissed in October. Harris, unlike the other victims, was killed in 2003.
Blair agreed to a nonjury trial in exchange for prosecutors not seeking the death penalty. Prosecutors also earlier agreed to dismiss charges against Blair in two other killings, three rapes and an assault.
Assistant Jackson County Prosecutor Michael Hunt said that in addition to DNA evidence, the state's case would rely largely on cell phone calls in 2004 from a caller who told police "details nobody else would know" and claimed to kill the women because "they're prostitutes."
"He calls them scum," Hunt said. "It's a disgrace, he says."
But defense attorney David Kenyon said evidence would lead to more than a reasonable doubt about Blair's involvement in the slaying. DNA evidence on some of the women would point to five people other than Blair, Kenyon said in his opening statement.
Blair has denied involvement in the killings, and sat quietly between his lawyers during the trial, which is being heard by Jackson County Circuit Judge John R. O'Malley. Several family members and friends of the victims also were on hand for the trial, which was expected to take about one week.
Joe Heikes, then a director of engineering operations for T-Mobile in Kansas City, testified about how police asked for his help in September 2004 in tracking down the cell phone signals from the man who had been calling 911 and telling police where to locate the women's bodies.
Heikes said he was first able to determine that the phone belonged to a Lee's Summit landscaping company and that it had been stolen. He described how he and police also tried to locate where the calls came from with a complicated series of "trial and error" test calls from approximate locations.
Hunt said one of the calls was determined by police to have come from an area near the home of one of Blair's relatives.
But under cross-examination by Kenyon, Heikes said the technology available now to make such determinations was not in place in 2004 and the calls could not be reliably traced to the Blair house.
"It wasn't very conclusive," Heikes said about the testing. "I was frankly disappointed in what we were able to determine."