The Hinsdale woman prosecutors say was at the center of Jeffrey Keller's plot to kill Bloomingdale resident Nate Fox spent most of Friday on the witness stand in DuPage County court.
Kathryn "Katie" Cole spent most of the time denying she ever had anything more than a very brief professional relationship with Fox, despite Keller's "obsession" and accusations that she was seeing Fox behind Keller's back.
Keller is charged with five counts of first-degree murder in the December 2014, shooting death of Fox, a 37-year-old car salesman and former International Basketball League player, outside Fox's Bloomingdale townhouse.
Cole, who is married, testified that she and Keller became friends in 2010 when their daughters played on the same soccer club.
While their communication started primarily about their children, the two eventually began sharing hundreds of electronic communications a day between 2010 and Jan. 11, 2015.
Prosecutors read and displayed dozens of those messages in court Friday.
On a "handful" of occasions, Keller and Cole engaged in "petting," but Cole said the relationship was never sexual.
In fact, she said, there was a period where she considered Keller her best friend.
During this time, Cole said, she told Keller about the gregarious Fox, who had come to work in her Hinsdale State Farm office.
Cole said she never thought much about the particular conversation until some time in October 2013, when Keller became insisting that she was seeing Fox behind his back, accusations that angered and confused her.
"He was one of my best friends. Why was he accusing me of such a terrible thing?" she said, "I was befuddled. I was angry. I didn't understand it."
But prosecutors say Keller became obsessed with Fox and the thought of Cole being with him. So much so, they said, that Keller had a GPS device placed on her car so he could see where her car was when he thought she was seeing Fox.
That all came to a head, prosecutors say, around 9:30 p.m. Dec. 22, 2014, when Keller hid in wait for Fox to pull into his Bloomingdale garage before shooting and killing him.
Within a half-hour of the murder, Keller texted Cole "Board meeting all done. How are you?"
And 15 minutes later he texted her asking her "How are the cookies?" a reference to the Christmas cookies she told him earlier that she was baking.
Cole said she was shocked to learn about Fox's death Dec. 27 when a co-worker emailed a link to story about the slaying. When told Keller was charged with the murder, she told detectives "(she) didn't believe it" because some time had passed since Keller had made an accusation about her seeing Fox.
The trial resumes Tuesday when prosecutors are expected to play videos of Keller's confession to Bloomingdale police.