(CNN) -- New Mexico authorities have identified seven of 11 slain women whose remains were discovered several months ago in shallow graves in west Albuquerque, but have yet to identify a suspect in their killings, police told CNN on Thursday.
The bodies of Candelaria, Chavez, Elks, Marquez, Nieto, Romero and Valdez were all ID'd by New Mexico police.
A dozen victims -- 11 women and the unborn child of one of them -- were found on a 92-acre parcel west of the city in February, police said.
Albuquerque police spokesman John Walsh said Thursday that police were considering all the deaths homicides, and believe they are linked because of the proximity of where the bodies were buried and how they were buried.
"It's ... likely that the same individual committed the same crimes," he said, "But we have to leave all possibilities open."
The victims were linked through drugs and prostitution, he said.
Police identified the women as Victoria Chavez, Michelle Valdez, Veronica Romero, Cinnamon Elks, Julie Nieto, Doreen Marquez and Monica Diana Candelaria.
Walsh said authorities estimate that the killings occurred somewhere between 2001 and 2004.
"We have to leave it wide at this point," Walsh said of the time frame.
In February, a woman walking her dog on the property -- which had been graded in preparation for development -- discovered a bone, police said. The office of the medical investigator determined that it was human.
The bodies were discovered afterward.
The killings have been featured on "America's Most Wanted," Walsh said. A task force in Albuquerque has been assigned to the cases, he added.