Authorities announced Wednesday morning that a Kentucky man killed himself earlier this month after fatally shooting his ex-girlfriend as she left her apartment in north suburban Lake Forest.

About 6:20 a.m. Jan. 3, 33-year-old Ryan Zike walked up to his former girlfriend, 27-year-old Claire VanLandingham, as she was leaving her apartment in the 600 block of North Western Avenue, according to Lake Forest police.

Following a brief conversation, Zike pulled out a semi-automatic pistol and shot VanLandingham multiple times, police said. Zike then shot himself in the head.

A 37-year-old Highland Park man who worked with VanLandingham witnessed the initial shooting as he was waiting to pick her up, police said. Moments after Zike turned the gun on himself, the man rammed him with his Land Rover Discovery "to avoid being shot."

The man, who is an active member of the U.S. Navy, tried to revive VanLandingham after striking Zike, police said. He also ran to a nearby business and asked people to call authorities.

In addition to the gun he used in the shooting, Zike was also found with another pistol and a knife, police said. He had a valid Kentucky concealed carry permit.

Preliminary autopsy results released Jan. 3 indicate that VanLandingham died from injuries related to her wounds, police and the Lake County Coroner's Office said.

An autopsy was then performed on Zike the following day. Preliminary results indicate he died from a self-inflicted gunshot wound to the head, authorities said. He didn't suffer major trauma from being struck by the Discovery.

Zike and VanLandingham were involved in a previous dating relationship, police said. For a time, they lived together in Lake Forest. Zike ultimately moved out of VanLandingham's apartment to live with his family in Louisville, Kentucky.

An investigation into the murder-suicide is ongoing.