Authorities have discovered that the bodies of 12 people found in troubled Ciudad Juarez over the last few months are those of girls and women, leading many to worry that young females are being specifically targeted.

In a statement Monday, the special prosecutor assigned to investigate crimes against women (created when authorities failed to solve earlier slayings) said DNA testing was used to identify the remains of six of the victims. It was determined that the victims were between the ages of 15 and 19 and were reported missing in 2009 and 2010. The remains of the other victims could not be identified due to decomposition.

Cause of death was not given for any of the victims, though Ciudad Juarez appears to have become the frightening home of women’s disappearances in Mexico. As authorities from Juarez struggle to solve or stop the slayings of women and girls, many are left wondering: Is there a serial killer in Juarez?