Witness Steve Crawford, an Overland Park jiu-jitsu instructor, demonstrates the rear naked choke hold maneuver on Assistant Attorney General Nola Wright at her request during cross-examination in the trial of Matthew Jaeger, Tuesday, Aug. 4, 2009, in Douglas County District Court. Crawford, a former instructor of Jaeger's, was brought in to testify about Jaeger's proficiency in jiu-jitsu.

A jiu-jitsu instructor testified on Tuesday that a kidnapping and aggravated battery defendant had participated in some of his classes and learned how to perform a choke hold.

Prosecutors allege that former Kansas University student Matthew Jaeger broke into a Lawrence apartment on Oct. 9, 2007, and attacked his ex-girlfriend, who is now 23. They claim he severely mutilated her vagina and pelvic region and dragged her from her apartment after he found her with another man.

He faces charges of aggravated kidnapping, aggravated battery, aggravated burglary and making a criminal threat in a trial that will enter a sixth day of testimony Wednesday in Douglas County District Court.

Jaeger’s defense attorneys have said their client found the woman injured and was trying to help her.

On Tuesday, prosecutors put Overland Park jiu-jitsu instructor Steve Crawford on the stand to demonstrate a basic choke hold. Last week, the victim testified that Jaeger choked her until she was unconscious. She said she woke up later with injuries.

“We do cardiovascular chokes. It slows down the blood flow to the brain,” Crawford said.

The choke hold can be applied to someone’s neck from behind in a few seconds, and it would cause a person to feel light-headed, as though the person had stood up too quickly, he said.

Crawford demonstrated the hold for jurors on Assistant Kansas Attorney General Nola Wright and defense attorney Michael Saken. He said he had never seen the hold render someone unconscious for more than a minute.

“The application of the hold would not result in a loss of longer-term memory?” Saken asked.

“No,” Crawford replied.

Also during Tuesday testimony, Michael L. Shanks, a Lawrence police officer, showed jurors photos that he took of the woman’s apartment the night of the attack. Shanks said he discovered blood droplets in the apartment parking lot, as well as in her dining room, kitchen, hallway, bathroom and bedroom.

The photos also show a broken window at the apartment. Pieces of the window had fallen into the apartment near the dining room table.

During cross-examination, defense attorney Pedro Irigonegaray asked Shanks if Dylan Jones, the man with Jaeger’s ex-girlfriend that night, ever told him Jaeger threatened to kill him during a confrontation. Prosecutors have charged Jaeger with one count of making a criminal threat against Jones.

“I didn’t record any, no, and I don’t recall any, no,” Shanks said.

In answering another question from the defense, the officer also said he collected two glass smoking devices and apparent marijuana in Jaeger’s ex-girlfriend’s apartment, but police never tested the items or charged anyone for possession.

Jurors also viewed a recording of Evan Carroll, Jaeger’s childhood friend who was driving Jaeger’s car after the attack. Jaeger and the woman were in the back seat of the car when police pulled it over. Carroll testified Monday that he saw Jaeger break the window to the apartment, but he said she got in the car with them willingly to try to get help.

In the recording of his police interview in 2007, he described pulling Jaeger away from the woman to try to make him leave the apartment.

In the interview, Carroll said he noticed later that she was bleeding, and he wanted to get her help.

“As far as what happened up there between them, I personally, honestly did not see it,” Carroll told police.

Wednesday’s testimony will begin at 9:30 a.m. with defense attorney Michael Saken questioning Lawrence police officer Todd Polson about his interview with Carroll.