A Cook County Judge approved the arrest warrant for Ermak, 64, for two counts of first degree murder, according to Buffalo Grove police.
Police released Ermak's photo and car information Tuesday. He is believed to be driving a white 2019 Nissan Versa hatchback with a Florida license plate reading KCFK75 that he recently rented in Minnesota, police said.
Ermak is described as 5 ft. 10 in. to 6 ft. tall with gray hair, police said. He was wearing dark clothing, a dark jacket, and a dark baseball cap, police said. He should be considered armed and dangerous.
Police identified the victims as Nataliya Ermak, 55, and her husband Roman Frid, 69. Police said Anatoliy Ermak is Natalyia's ex-husband.
According to court records reviewed by ABC7 Eyewitness News, Anatoliy Ermak was previously convicted of misdemeanor disorderly conduct in Minnesota in May 2007. Minnesota police records also show officers were called for two domestic incidents between the Ermaks in 2007, and Anatoliy was once arrested for domestic assault, with Nataliya listed as the victim.
WATCH: Buffalo Grove police provide update on double homicide
Police were sent to a parking garage of a building in the 150-block of Lake Boulevard at about 11:30 p.m. after a resident saw two people unresponsive near a vehicle with blood on the ground. Officers arrived and determined that a man and woman had been shot to death.
Police said surveillance video shows the suspect followed the victims' car into the garage on foot. The victims get out of their car at about 8:15 p.m., the shooter approaches them and they have a brief conversation before the suspect shoots them multiple times. Video shows him flee the scene on foot, police said.
Buffalo Grove police said they are following up on several leads but do not yet have anything solid about Anatoliy Ermak's location or which direction he may be traveling.
Investigators said this was a targeted attack and that the suspect acted alone. While they do not believe there is a greater danger to the neighborhood, they are increasing patrols in the area to help ease concerns from residents worried about neighborhood safety.
Anyone with information is asked to contact Buffalo Grove police at 847-459-2560.
Anonymous tips can be given to Lake County Crime Stoppers on-line at www.lakecountycrimestoppers.com or by calling 847-662-2222.