Police have identified a suspect in the murders of four women whose remains were found in Fairfax and Harrisonburg counties.

During a joint press conference on Friday, Fairfax County and Harrisonburg County police identified Anthony Robinson, 35, as the suspect in the deaths of Allene Elizabeth Redmon, Tonita Lorice Smith, Cheyenne Brown, and a fourth victim who has yet to be positively identified. He is currently in custody at the Rockingham County Jail in Harrisonburg.

According to Fairfax County Police Chief Kevin Davis, Robinson allegedly met the three identified victims at motels before they were killed, and transported their remains to different locations in a shopping cart. Police are referring to Robinson as a serial killer and said an investigation is ongoing into additional suspects and victims.

“The good thing is he’s in custody,” Davis said. “The challenge that remains is identifying other victims.”

Robinson was first arrested by Harrisonburg police on Nov. 23 and charged with two counts of first-degree murder for the killing of Redmon and Smith. Both women were found dead in a vacant parking lot in Harrisonburg.

On Nov. 30, the Metropolitan Police Department contacted Harrisonburg police regarding a missing D.C. woman, Cheyenne Brown, who D.C. police believed had last contacted Robinson. Both departments began working with Fairfax County police, after video footage from Sept. 30 showed Brown, 29, with Robinson at the Huntington Metro station in Alexandria, and cellphone data placed her on Richmond Highway, near the Moon Inn.

On Wednesday this week, Fairfax County police found human remains in a container near the Moon Inn. Brown, who was four months pregnant at the time of her disappearance, was identified after family members recognized tattoos.  Remains of a second person were found in the same container, but police have not yet been able to positively identify the fourth victim. Brown has also not been confirmed through DNA analysis yet, according to police.

Robinson has not yet been charged with the two alleged murders in Fairfax County, Davis said. According to Harrisonburg Police Chief Kelley Warner, Robinson does have an attorney but has not provided a statement. He has had numerous addresses, ranging from D.C., to Prince George’s County, to New York.