An Evanston man was charged with murder Friday after surrendering himself to police at the scene of the stabbing death of a man whose house he lived in for eight years, police said.

Ernst Thomas Wagner, 40, was charged with one count of first degree murder in Evanston Police Department’s investigation of the death of retired Niles North High School teacher William Strong, 67, of 1819 Brummel St. The Cook County Medical Examiner’s office determined that Strong died of multiple stab wounds and ruled the death a homicide. Wagner had lived in Strong’s home as a tenant for about eight years, said Cmdr. Art Elam of EPD.

A judge ordered Wagner held without bond during a hearing Saturday. At a second bond hearing Tuesday, a judge set a $500,000 cash bond for Wagner, said Cook County State’s Attorney Office Spokesman Jerry Lawrence.

Strong died at about 3:30 p.m. Friday, Elam said. Police were notified of the death by a relative of Wagner’s, whom Wagner had spoken to about the incident, Elam said. Police arriving at the Brummel Street home found Strong’s body and also found Wagner, who was arrested without resisting.

Strong taught Spanish at Niles North High School in Skokie from 1964 to 1992. Steve Rosenzweig, also a retired Niles North Spanish teacher, worked with Strong for 15 years. He said Wednesday that Strong was “absolutely brilliant … probably the smartest man I’ve ever met.” Rosenzweig said he attended a funeral service for Strong on Wednesday. He also said Strong “loved the kids — he dealt with them in a very professional manner.”

Wagner’s father, also named Ernst Wagner, said Strong let Wagner live at the house. “I don’t really know if he paid any rent, but he did all the maintenance in the house,” he said.

Assistant Public Defender Jim Mullenix, who is currently assigned to Wagner’s case, said the State’s Attorney’s office at the Tuesday hearing petitioned the court to deny Wagner bond. Mullenix said the State’s Attorney’s petition claimed that Wagner had a mental condition and had at some point admitted to killing Strong. Lawrence said Wagner has no criminal record in Cook County.

Wagner’s father said his son had a long history of schizophrenia and manic depression and has to take pills to remain mentally stable. The suspect called his mother at the time of the homicide and told her he was being attacked, the elder Ernst Wagner said. Wagner thinks that at that time, his son may have been hallucinating because he had not taken his pills.

Wagner’s case is scheduled to go before a grand jury Aug. 4. He is scheduled to appear Aug. 6 at Circuit Court in Skokie.

City Editor Scott Gordon is a Medill junior. He can be reached at [email protected].