RALEIGH — The man accused in two of Raleigh's unsolved murders may be linked to other killings and a string of sexual assaults. The mother of one victim says John Williams' trail leads directly to her daughter.

Williams, a drifter from Georgia who was living in a homeless at the time of his arrest, is the city's first serial killer. They're working now to gather evidence to show Williams killed four of the six black women found murdered in downtown Raleigh last year. But, police are not the only ones trying to connect Williams to more crimes.

Elizabeth Todd, the mother of homicide victim Dawn Grandy, told WRAL-TV5's Bret Baier that she has no doubts Williams is responsible for her daughter's death.

Williams is currently charged with the murders of Patricia Ashe and Deborah Elliott, but Raleigh police say he is also the prime suspect in two other murders still unsolved, those of Grandy and Cynthia Brown.

Todd says her daughter used to live with Williams. Before Dawn's body was found in July, Todd says she would see Williams following Grandy around all the time. In addition, Patricia Ashe was one of Dawn's best friends.

Police conducted 6,000 interviews and beefed up downtown patrols before luck led to Williams' arrest.

Police refused to link any of the murders together until just recently. Now, they say they have a serial killer behind bars. Criminologist Dr. Margaret Zahn says it's understandable that police would put off making such an announcement.

Zahn says the portrait of a serial killer is often difficult to figure out.

``We have our man,'' said police Capt. Dennis Ford. ``We have him off the street at this point. People should feel comfortable at this point that we have our perpetrator.''

Ford said the slayings were not tied together until Williams was arrested and women he allegedly assaulted helped officers.

In addition to the newest murder charge, police also have charged Williams with two additional rapes, two attempted rapes, three counts of assault with a deadly weapon with intent to kill, inflicting serious injury, one count of assault with a deadly weapon with intent to kill and one count of first-degree sex offense. These charges results from crimes that occurred between October 1995 and November 1996.

Williams has pleaded innocent to killing Elliott and has not entered a plea in the second slaying. In all, he is suspected in the deaths of or attacks on nine women.