(CBS) — Police issued an Amber Alert for two toddlers who were last seen with their father, who is a person of interest in the fatal shooting of their mother.

The alert was issued Wednesday night for 2-year-old Jordyn Washington, a girl, and 3-year-old Lynn Roby, a boy. Police said they were taken by their father, 46-year-old Lynn Washington, around 2 p.m. Wednesday.

READ MORE: Fourth Student Dies In Michigan High School Shooting

They were last seen in a silver 2004 or 2005 Chevrolet Malibu or Impala.

A protective order issued on Nov. 30 barred Washington from having any contact with the children, but police said he picked them up from a family friend about 12 hours after their mother, 27-year-old Lakisha Robie, was killed in a shooting at a BP gas station at 167th and Pulaski.

Lakisha Roby

Police said the friend did not know about the protective order.

Markham Police Chief Mack Sanders said Robie and Washington argued in a car shortly before she was shot.

READ MORE: Jussie Smollett Trial: CPD Detective Recounts Actor's Description Of Attack Police And Prosecutors Have Called A Hoax

Three-year-old Lynn Roby, 2-year-old Jordyn Washington, and 40-year-old Lynn Washington are the subject of an Amber Alert. Police said the boy and girl were taken by their father Wednesday afternoon, hours after their mother was shot and killed. (Credit: Illinois State Police)

Police said Washington is a person of interest in Robie’s death, and they want to question him about the shooting. They said Washington should be considered armed and dangerous.

Washington is black, with brown hair and brown eyes. He is 5-foot-9, weighs about 180 pounds, and has tattoos on his neck, chest, and arms.

Sanders said the potential danger is clear

“The children’s mother is deceased now for one. For two, he has an active order of protection that he knows about. For three, he went and got those kids when he wasn’t supposed to have them period.”

MORE NEWS: Supreme Court Hears Arguments In Major Mississippi Abortion Case

The couple also have a 7-year-old daughter, who is safe, police said.