It's day two of testimony in the trial against a former police officer, charged with killing a Kentucky man.
Prosecutors say Steven Rios slashed Jesse Valencia's throat in 2004.
Valencia was a student at the University of Missouri where police say the two were having an affair at the time.
This is the second trial for Rios. His first conviction was overturned.
Meanwhile Valencia's mother, Linda Valencia, says going through a second trial is emotionally draining.
"I know who murdered my son and there's no doubt in my mind. There was no need to have this new trial," Linda says.
The trial is expected to finish on Friday.