Marti murder case can go to trial, judge rules

October 5, 2018

A San Luis Obispo judge ruled there is enough evidence to try South County man Robert Koehler for the murder of 26-year-old SLO woman Kristen Marti. [KSBY]

Marti disappeared in January after she was last seen alive in the 1800 block of Perfumo Canyon in San Luis Obispo. Koehler is believed to have been the last person to have been with Marti while she was alive, and he admitted to investigators that he spent time with the woman on Jan. 9, though he claims he did not meet her in Perfumo Canyon.

The San Luis Obispo woman had been missing for nearly three months when officers found her body in a creek near Perfumo Canyon during a large search of the area. Later in the spring, Koehler and his wife fled the Central Coast. Koehler was arrested in Minnesota and extradited to SLO County.

Koehler is charged with murder and accused of using a knife to slit Marti’s throat. He has pleaded not guilty.

On Wednesday and Thursday, a preliminary hearing in the case took place in San Luis Obispo County Superior court, at the conclusion of which Judge Craig van Rooyen ruled the case can go to trial.

During the first day of testimony, police investigators said Marti was known to prostitute herself for money and drugs and that Koehler was known to seek women for sex on Craigslist and Tinder, even when he had a pregnant wife. Marti and Koehler had reportedly been communicating via an anonymous messaging app prior to meeting on Jan. 9.

A forensic toxicologist testified that Marti had cocaine, morphine, methamphetamine and an animal tranquilizer in her system at the time of her death.

On Thursday, SLO County District Attorney’s Office Detective Casey Neall testified that two internet bookmarks found on Koehler’s phone referenced animal tranquilizers. Koehler told detectives he researched them for a friend who had a pit bull that would bite the ceiling fan and that he never bought the tranquilizers.

Koehler’s phone also contained hundreds of photos of naked women and four images of Kristen Marti. Neall also testified that Koehler admitted he met with Marti for sex and drugs.

Detectives also found hundreds of letters Koehler wrote, some of which reference criminal acts with similarities to the murder of Marti. It is believed that Koehler wrote 485 letters between 2005 and 2010 while he was previously incarcerated.

Police Detective Caleb Kemp read excerpts of some of the letters while testifying on Thursday.

“Cut neck with box cutters,” one letter states.

“As you suffer alone under the ground, covered with dirt where you’ll never be found,” another letter states.

The letters also discuss ways to avoid getting caught doing something illegal, as well as Koehler’s hatred for women who charge money for sex.

Sheriff’s Detective Jason Caron testified Marti had rocks over her body and was in flowing water when officers found her. It appeared Marti’s throat had been cut while she was still alive.

Detectives say Koehler has given multiple accounts of where he went with Marti and where he was at about the time of her disappearance. One of the women whom police interviewed said she previously performed sex acts for Koehler in Perfumo Canyon, according to testimony.

Koehler’s lawyer, Trace Malone, said the other women Koehler met up with in the past for sex and drugs never said he attacked them. Malone said there was no evidence that Koehler was with Marti in Perfumo Canyon.

Malone argued Koehler was guilty of solicitation and using drugs, but not of homicide. The defense attorney said Marti was an active drug user and in the neighborhood of a house where drugs users lived and where a suspicious overdose had recently occurred. Malone argued Marti’s associates could have dumped her body in the creek after she overdosed.

Koehler is due to return to court on Oct. 15.