DALLAS (AP) -- The south Dallas crime-watch volunteer accused of four rapes preyed on women as they walked late at night through the neighborhood he appeared to protect, sometimes assaulting them while he held a gun to their heads, according to police affidavits released Wednesday.
Van Dixson, 38, faces four counts of aggravated sexual assault in the attacks in his neighborhood of Fair Park, where he was known to some residents for walking the streets at night, ostensibly to watch for criminals.
Instead, according to Dallas police documents, he grabbed four women late at night and forced them to perform oral sex. The attacks were among nine this summer that police believe were committed by the same man.
In one late August attack, he allegedly raped a woman after first trying to rob her and then sending her two children away.
The woman said a masked man approached her, brandished a handgun and demanded money Aug. 30 while she was walking with her children. When she fumbled with her shirt looking for money, the woman said, the man told her children to leave and then raped her in a nearby alley.
In another June attack, he allegedly grabbed a woman who was walking home and became separated from her friend.
He demanded money from the woman, then forced her to perform oral sex while pointing a gun at her head, another affidavit says.
Finally, in a separate August attack, he forced two women walking together around the back of an abandoned home, demanded that they take off their pants and ordered them to perform oral sex, according to two other affidavits.
Dixson was arrested Tuesday in a Baton Rouge, La., motel. Officials said he was still being held Wednesday in Louisiana, and it was not clear exactly when he would be extradited to Texas.
At a news conference Wednesday evening, Police Chief David Brown described the complexity of the investigation detectives encountered before they could discern a pattern to the attacks and suspect Dixson of committing them. The explanation came in response to some community criticism over the pace of the investigation.
Brown gave a timeline of the nine assaults covered by the investigation, dating to a June 22 attack. It included almost a two-month hiatus, from June 30 to Aug. 20, when no sexual assaults were reported in the area after the first two attacks. Consequently, police had no evidence on which to base a conclusion that a serial rapist was at work, Brown said.
A tipster led police to interview Dixson at police headquarters Sept. 4. A DNA specimen was taken from him that day, and although he was released with no charges, he became a person of interest, Brown said.
First test results Sept. 7 linked Dixson to one rape, but police were unable to locate him, Brown said. At first, federal officials believed he had fled to Mexico before marshals tracked him to Louisiana.
Police say DNA evidence so far has linked Dixson to four rapes. They are awaiting DNA tests from two other cases; in three other cases, such evidence wasn't available.
In the early 1990s, Dixson, a convicted robber, was accused of raping a woman at gunpoint, according to the former prosecutor in that case.
"The case made a deep impression on me," said Colleen Skinner, the prosecutor in that case who is now a private attorney in Dallas. "It was just so brazen."
But the woman's death in a freak accident -- a lightning strike -- made prosecution impossible, Skinner said.
"My hands were tied," Skinner said. "Even if the rape kit had shown he was the perpetrator, I would need a witness to tell the jury that it wasn't consensual. I would need a witness to tell me, 'He forced me.' I would need a witness to testify, 'It happened in Dallas County.'"
Police spoke to Dixson about this summer's rapes in south Dallas after a tipster identified him as a possible person of interest. But police have said they had to release him after their interview because they didn't have charges to hold him on. Dixson did voluntarily submit a saliva swab, which was then used to link him to DNA from four rapes.
Dixson has been part of the area's neighborhood crime-watch group, the Mill City Community Association, since January. The group's president, Alendra Lyons, called his arrest a "relief to the community."
State criminal records show Dixson was convicted of aggravated robbery in 1993. He served more than 10 years in prison, a state prisons spokeswoman said. He was also arrested as recently as last month on a deadly conduct charge, according to Dallas County records.
Lyons said she wasn't aware of Dixson's criminal past and that the incident had spurred her group to look into whether it could afford background checks on new volunteers.
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