A border agent was arrested early Saturday in South Texas by officials searching for a serial killer in the Laredo area.
Alaniz said investigators were still trying to determine a motive for the killings, and all the women in the case are linked to the sex trade.
Juan David Ortiz, an intel supervisor for the Border Patrol, was found about 2 a.m. when state troopers tracked him to a hotel parking lot in the border city of Laredo, Texas.
All of these cases are related to the almost two week murder investigation of two other women who were found killed in a rural part of Webb County. He fled police after the fifth woman he abducted escaped and informed authorities about her plight.
A senior US Customs and Border Protection (CBP) official, Andrew Meehan, said in a statement that the agency was cooperating fully with the investigators.
Authorities didn't disclose the victims' names or nationalities but said they may have been prostitutes.
The district attorney's office intends to charge Ortiz with four counts of murder and one count of aggravated kidnapping.
The sheriff said that Ortiz was a 10-year veteran supervisor with Border Patrol, local NBC/ABC affiliate KGNS reported.
According to the District Attorney all of the women were prostitutes who were allegedly picked up by Ortiz.
"Our sincerest condolences go out to the victims' family and friends".
I also intend to speak with the General Inspector of DHS who is working on this matter, to express my concern that this is the second case this year involving a border patrol agent who has killed someone in Laredo.
"We do consider this to be a serial killer", Alaniz said. Authorities believe he acted alone.
The Texas Department of Public Safety, whose Texas Rangers are investigating, did not return several messages seeking comment.