Van Dralan Dixson is shown in this photo provided by the Dallas Police Department. Authorities have located a car belonging to Dixson, a crime watch volunteer charged in one of nine sexual assaults in South Dallas. AP Photo/Dallas Police Department This photo shows the house on Baldwin Street belonging to rape suspect Van Dralan Dixson Monday, Sept. 9, 2013, in Dallas. Dallas police are searching for rape suspect Van Dralan Dixson, a crime watch volunteer, who has been charged with one count of aggravated sexual assault in connection to a rape and robbery in Fair Park. This photo shows Baldwin Street, where rape suspect Van Dralan Dixson has a home, on Monday, Sept. DALLAS (AP) - Dallas police said Monday night that DNA evidence has linked a crime-watch volunteer to four sexual assaults in a Dallas neighborhood where at least eight rapes were reported over two months, with more tests pending. Van Dralan Dixson, 38, remained a fugitive as of Monday night, said Dallas police Maj. Jeff Cotner. Dixson had been charged with one count of aggravated sexual assault relating to a rape and robbery in the Fair Park neighborhood, just southeast of downtown. Addressing reporters Monday night, Cotner said three more aggravated sexual assault counts had been filed against Dixson with bail set at $1 million for each count. Cotner also said police had taken Dixson into custody briefly last week and obtained a DNA sample from him, but did not have evidence to bring charges at that time. Cotner said DNA test results from two attacks were still pending, and no evidence was available from two other attack cases. Meanwhile, Cotner said, federal investigators are helping in the search for Dixson. Police are interviewing friends, family, other associates, his employer and tipsters for clues to Dixson's whereabouts, Cotner said. Dixson was charged with his first count Saturday, and his car was found abandoned the next day in a parking lot in Garland, a suburb northeast of Dallas. The car was impounded, and a warrant to allow a police search was pending, Cotner said. As a crime-watch volunteer, Dixson would patrol the streets several times a week, neighbors said. "He just walks every night, all night," one resident, Billy Washington, told Dallas television station WFAA. Every time I would look out my window, or out my door, he was walking. 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, didn't return messages Monday from The Associated Press. The group said Dixson's duties were limited to telling neighbors about the association, not patrolling at night - but neighbors told The Dallas Morning News that he was referred to as "neighborhood watch," and it seemed he was patrolling the neighborhood almost every night. State criminal records show Dixson was arrested and convicted of aggravated robbery in 1993. But he was also arrested as recently as last month on a deadly conduct charge, according to Dallas County records. County records also show that he filed for divorce three years ago, and it was finalized a few months later. A judge awarded Dixson custody of the couple's three children, who are now 21, 8 and 6. Dixson's attorney during the divorce, Tiombe Jones, said Monday that she didn't remember anything particular about Dixson or the divorce proceeding. Messages left on a cellphone listed for Dixson's ex-wife were not immediately returned. Authorities have said they believe one suspect committed the nine sex assaults that have been reported in the Fair Park area this summer. In each, the attacker approached his victims in the early morning hours, forced them to secluded areas nearby, and then robbed and sexually assaulted them. The assailant in each case was armed with a handgun, wore shorts and a T-shirt, and masked his face using various types of cloth, according to police. The victims said they were approached on foot. A $15,000 reward has been offered for information leading to arrests and an indictment in the cases.