Wichita ? Before Eric Leckenby killed his girlfriend’s ex-husband and them himself, he sent a letter to The Wichita Eagle describing his rage over a child custody dispute.

The Eagle received the letter Thursday, a day after the murder-suicide. Leckenby, 29, also left a will and testament where police would find it.

Police said Scott A. Smith, 34, the former husband, was dropping off his children at his ex-wife’s home about 7 a.m. Wednesday when Leckenby confronted him with a gun.

Leckenby chased down Smith, police said, shot and killed him in a parking lot, then took his own life before officers could stop him.

“He (Leckenby) had definitely put some planning into this,” Wichita police Capt. Nelson Mosley said Thursday.

In the letter to The Eagle, Leckenby said he was angry about the child custody dispute involving Smith and Leckenby’s girlfriend.

Neighbors and business owners witnessed the chase and shooting. At least seven people called 911, including the ex-wife who apparently was inside with the children when the confrontation began, police Lt. Ken Landwehr said.

“There is no indication that she was involved or had any knowledge about what was going to happen,” he said.