SYCAMORE, Ill. (AP) — A northern Illinois sheriff’s office has released DNA-inspired images of the possible appearance for the man who killed an 85-year-old woman and her son two years ago.

The DeKalb County sheriff’s office turned to Virginia-based Parabon Nanolabs to analyze DNA collected at the home of Patricia Wilson and 64-year-old Robert Wilson in Sycamore. The (DeKalb) Daily Chronicle reports the private lab developed images of a fair-skinned man with blonde hair and blue eyes at ages 18, 25 and 40.

The Wilsons were fatally beaten in August 2016, with her stolen car found days later near Chicago’s Lincoln Park Zoo.

Chief Deputy Andy Sullivan says the DNA samples are checked every two weeks by the FBI for matches and have ruled out some suspects. Sullivan says a detective continues to investigate.