Lyndon ? Attorneys for a man on trial for capital murder called his parents, ex-friends and a former co-worker as witnesses Monday, trying to bolster their case that he’d deteriorated mentally before the killings of his estranged wife and their two teenage daughters.

Defense lawyers contend James Kraig Kahler, 48, a former city utilities administrator in Weatherford, Texas, and Columbia, Mo., snapped because his wife, Karen, was having a sexual relationship with another woman and was pursuing a divorce. Kahler also is charged with killing his estranged wife’s grandmother.

The four victims were shot to death the weekend after Thanksgiving 2009 in the grandmother’s home just outside Burlingame, a town of about 930 residents some 20 miles south of Topeka. Prosecutors say the killings were premeditated and are seeking the death penalty.

Three former friends from Weatherford, Texas, said the Kahlers’ marriage crumbled after Karen Kahler began an affair with a fellow fitness trainer, Sunny Reese. The former co-worker, Michael Schmitz, from Columbia, Mo., said the defendant, who goes by his middle name, was “obsessed” with saving his family and distracted from his job there. Kraig Kahler’s parents described him as being depressed when he lost the job in Missouri and moved back to Kansas to live in the finished basement of their home outside Topeka.

But one former friend — who’d also had a relationship with Reese — said she formed an impression of Kahler as a “controlling” husband who saw his wife as a “trophy.” Jurors also heard testimony that Kahler expected sex with his wife at 8 p.m. every night and that she considered it “one of her chores.”

Defense attorneys planned to finish their case Wednesday but don’t know whether Kraig Kahler will testify.

His father, Wayne Kahler, said described his son as “down in the dumps” in the weeks before the killings and said he worked constantly on his parents’ farm, painting buildings, water tanks and even steel posts. The father testified that the family moved Kraig Kahler from his home in Columbia, Mo. because he was depressed.

“He wasn’t eating, I think, quite enough,” Wayne Kahler testified. “He was undernourished.”

The victims were Karen Kahler, 44; her grandmother, Dorothy Wight, 89, and the Kahlers’ daughters, Emily, 18, and Lauren, 16. Law enforcement officers and emergency medical personnel have said Wight and Lauren Kahler identified the defendant as the gunman.

The Kahlers’ son, Sean, now 12, escaped without physical injury. He testified that he saw his father shoot his mother.

In Kansas, unlike most other states, jurors are not asked to consider whether they believe a defendant understood his alleged actions were criminal. Instead, jurors consider whether his mental state kept him from forming the intent to kill a specific victim or victims and from reflecting on actions he might take.

According to testimony, Karen Kahler began a sexual relationship with Reese in 2008, before Kraig Kahler took a job as water and light department director in Columbia, Mo. Karen Kahler filed for divorce in January 2009.

Reese has testified her relationship with Karen Kahler turned sexual in summer 2008 and that Kraig Kahler was pleased and even once proposed three-way sex, something the defense strongly disputes.

Liz McAulay, a friend of the Kahlers’ in Weatherford, Texas, said she believes the affair started earlier and that Kraig Kahler didn’t know until McAulay told him. McAulay said she was upset about the affair because she’d been involved with Reese previously.

McAulay also testified that Karen Kahler told her that she had to account for every expense and that Karen Kahler’s friends viewed her as “Kraig’s trophy wife.” She said Karen Kahler viewed nightly sex with her husband as a chore.

Marina Coulter, another Weatherford, Texas, friend of the Kahlers, also said Karen Kahler confided that her husband expected nightly sex. But, Coulter added, “I didn’t know whether she was bragging or complaining.”

Both Coulter and her husband testified that they had thought the Kahlers had a good marriage and that Kraig Kahler was good husband.

But they recounted a party on New Year’s Eve 2008 when Karen Kahler invited Reese. The Coulters said the two women acted “friendly” and left the party shortly before Kahler did. The next day, with the two women present in the Coulter home, Kraig Kahler announced they were having an affair.

Dr. Siamac Vahabzadeh of Columbia, Mo., who prescribed medication for Kraig Kahler in March 2009 because of his depression, testified that he didn’t recommend hospitalization because Kahler didn’t appear to be a danger to himself or others at the time.

When questioned by prosecutors, the doctor, Schmitz, McAulay and the Coulters acknowledged that they’d had no contact with Kraig Kahler for weeks before the killings, and didn’t know his mental state at the time.