Police in Portland, Ore. have arrested Homer Lee Jackson, 55, in connection with the cold case killings of four woman 30 years ago.

The 1980s saw four unsolved murders of Essie Jackson, 23, Tonja Harry, 19, Angela Anderson, 14, and Latanga Watts, 29. The bodies of the four victims, all of them victims of sex trafficking were found across locations in Portland, Ore.

Now, more than three decades later, police believe that they have solved the cold cases thanks to forensic evidence and similarities in the cases, leading to Jackson's arrest on Thursday.

"The main thread that kind of is woven through this story is the fact that they were all victims of sex trafficking, and he would patronize services of these women and women like them, and he targeted them for that reason," Portland police Detective Meredith Hopper told CNN.

Portland police Sgt. Peter Simpson said that all of the four victims were African-American females in their teens or 20s. They had been involved in prostitution and had died of asphyxiation, either by drowning or strangulation.

The police feel that Jackson, who is being held without bond, may be responsible "for a countless number of other deaths," according to The Examiner.

"Detectives are asking the public to help with these cases by providing any information they might have about these four victims and about Homer Jackson, including people who have associated with him in the past few years and can talk about his routines, habits and places he frequents," Simpson said at a news conference, according to The Canada Journal.

Jackson's criminal history dates back to 1983.