KANSAS CITY, Mo. -- An employee at a trash-hauling company has been charged with strangling 12 women or girls from 1977 to 1993 in an arrest authorities said was made possible by new DNA technology.

Authorities said Lorenzo J. Gilyard preyed on prostitutes and teenage girls during his 16-year rampage, sexually assaulting all but one of the victims and strangling them with items including nylon stockings, shoe strings and wire.

The bodies -- most of them nude or partially clothed -- turned up in various places around Kansas City over the years -- an abandoned van, a field, a parking lot, a snow drift.

Eleven of the victims were prostitutes; the other was a mentally ill woman who roamed the streets and accepted rides from strangers. They ranged from ages 15 to 36.

The news brought relief to family members who had all but given up hope that someone would ever be arrested in the killings.

"It's a blessing," said Bessie Kelly, whose sister Naomi Kelly's body was found in 1986. "Thank God for DNA."

Gilyard, 53, was arrested Friday and charged the next day with 10 counts of first-degree murder and two counts of capital murder, the law in effect at the time of two of the killings. Gilyard was held without bail.

If Gilyard is convicted of all the murders, he would be the worst serial killer in the city's history, police said.

Prosecutors have not determined whether they will seek the death penalty. Police are investigating to see whether other killings might be linked to Gilyard, who was in and out of jail and prison in the late 1970s and the 1980s on charges ranging from molestation and sexual abuse to burglary and assault.

"We aren't going to stop because we have 12 charges," police chief Rick Easley said.

Police did not connect any of the cases until 1994, when two of the homicides were linked. They connected the rest during the last 10 months.

The killings were sporadic. Eight of the victims were killed in a two-year period in 1986 and 1987, and only one victim was killed after that.

Police said they linked Gilyard this month after analyzing a blood sample taken from him in 1987, when he was a suspect in the death of one of the women he is now charged with killing.

The technology to compare that sample with DNA found on the victims' bodies did not exist until 2000, officials said. A federal grant in 2003 paid for authorities to analyze DNA samples in the old cases.

"This is another example as to what DNA evidence can do for us in law enforcement and really for the entire community," prosecutor Mike Sanders said. "In this circumstance, it wasn't investigative leads per se that led to these charges, it wasn't additional witnesses that came forward."

Gilyard had worked for Deffenbaugh Disposal Service since 1986, starting out as a garbageman and working his way up to supervising several trash crews, company spokesman Tom Coffman said.

Coffman described him as reliable, friendly and "quick to make a joke."

"These allegations just don't square with the Lorenzo we all know, and it's pretty difficult to get your arms around this situation," Coffman said.