Prosecutors say James Emerson used a large piece of cement to beat Rhonda Mertes to death back in 1999. Saturday they showed it to the jury.

Wausau Police Detective Matt Barns took a large piece of cement from an evidence bag. Then retired Detective Charles Jones identified it as the blood covered object found next to Rhonda’s body.

The state says 44-year-old Emerson beat the victim to death after sexually assaulting or trying to sexually assault her. They say they have a witness who will testify Emerson admitted to hitting Rhonda with brick.

Detective Jones was the point man at the start of the investigation. With the help of pictures and graphs, he detailed careful steps he took to protect the scene and evidence, including sealing the victim’s hands in bags.

Prosecutors say Emerson’s DNA was found under Rhonda’s fingernails, but under cross examination, Jones testified it was several hours after he was called to the crime scene that those hands were covered.

The defense also tried to shed light on possible problems with evidence. Defense Attorney Peter Thompson asked Jones about a vial of blood not included in the sexual assault evidence collection kit sent from the Wausau Police Department to the State Crime Lab.

Jones answered he had no knowledge of the problem. In redirect, prosecutors got Jones to testify a blood standard can sometimes come from other places than the sexual assault kit.

The first police officer and EMT at the scene testified as well.

Rhonda’s daughter also took the stand, to testify of how normal life was the day before her mother was killed and the nightmare the day after.

The trial is scheduled to resume on Monday with 8 people expected to be called to the stand. Among them are the victim’s boyfriend, the county medical examiner and the owner of the bar where Rhonda was last seen alive.