CASSOPOLIS — Karessa Warner didn’t know it at the time, but she might have been dating a murderer in February 2010.

The 22-year-old ex-girlfriend of Keith James Lintz testified Thursday that Lintz might have implicated himself in the murders of Niles couple John and Carolyn Tarwacki with a statement he made to her in March of 2010.

Lintz, 28, of Niles, is being tried on two counts of first-degree murder in Cass County Circuit Court for the deaths of the Tarwackis at their home on Carberry Road in Howard Township Feb. 5, 2010.

On day three of the trial, Warner, a state witness, said she met Lintz in February 2010 and they began living together in an apartment on Carberry Road shortly thereafter.

Warner brought Lintz to a birthday party for her oldest son being held at Warner’s mother’s house in March 2010.

While at the party, Warner said her mother pulled her aside and told her to get Lintz out of her house because he was the No. 1 suspect in the double homicide.

A couple days later, Warner repeated to Lintz what her mother had said. Lintz got upset and said, according to Warner’s testimony, “The only reason I’m the No. 1 suspect is because they have my footprints going through the yard.”

Warner said she didn’t know what to think because, at the time, she didn’t know much about the case.

Warner later asked Lintz why his footprints would be in the Tarwacki’s yard.

Lintz told Warner he was headed to his grandfather’s house. Warner said the answer didn’t make sense because Lintz wouldn’t have to go through the Tarwacki’s yard to get there.

Warner said she and Lintz split up a short time later.

Defense attorney Greg Feldman’s cross-examination focused on Warner’s past troubles with methamphetamine use. Warner admitted she has been a meth addict, but wasn’t using at the time she and Lintz were together. Warner was later arrested and sent to prison on a meth charge. She is currently on parole for the conviction.

The state also called on forensic scientist Troy Ernst to testify Thursday. Ernst said he digitally enhanced a picture of one of the footprints left in the snow behind the Tarwacki’s house. He found what he believes to be the number “12” in the image.

However, when cross-examined by Feldman, Ernst said it is possible the second number could be a “3” or a “7.”

Another state witness, Christine Gregory, with Michigan State Police forensics, testified that tread from the footprint had a similar design to a “Route 66 Oxford Leather” shoe. She said it is common for shoes to have a number on the sole indicating the shoe size.

During cross-examination, Gregory said it is possible a different type of shoe made the footprint.

Michigan State Police Det. Fabian Suarez, the lead investigator on the case, testified that police seized a pair of shoes from Lintz during a traffic stop. While the shoes couldn’t be traced to the homicides, Suarez said they were size 12.

The trial continues today in Cass County Circuit Court.