(Portland, OR)  --  A man is being linked to the deaths of four Portland women in the 1980s, and police say there may have been other victims.  Fifty-five-year-old Homer Lee Jackson has entered not-guilty pleas on 12 counts of aggravated murder.  The victims included Essie Jackson, Tonja Harry, and Angela Anderson, who were killed in 1983, and Latanga Watts, who died in 1987.  Portland police told KGW-TV that Jackson has been connected to all four murders through forensic evidence and other information, and DNA is being used in an attempt to solve other murder cases.