Jurors got a look inside Amanda and Grant Hayes' apartment where investigators believe Laura Ackerson was killed.
Investigators believe the couple dismembered her body in their hall bathroom and later cleaned the apartment with bleach, trying to get rid of any evidence left behind.
"It wasn't set up as a bathroom. There was not a trashcan or shower curtain, any floor mats," said CCBI Senior Agent Shannon Quick. "There were a couple of bottles of shampoo but that was about it in that bathroom."
Investigators showed the contrast between the nearly empty and excessively clean hallway bathroom with the other one in the Hayes' apartment, which was cluttered and messy.
Investigators later found in a dumpster, the bath mats and the shower curtain they believe were missing from the Hayes bathroom. They also found areas of the carpet that appeared to have bleach stain and a spot on a bed comforter that tested positive as likely being blood.
Also Thursday, an environmental investigator from Texas testified that surveillance cameras set up to catch people dumping illegally in a creek near Amanda's sister's home caught Amanda leaving boxes of muriatic acid in the deserted area on a dead-end road.
Investigators say the couple poured acid on Ackerson's body to speed up the decaying process.
Towards the end of the day, prosecutors showed a handwritten letter with Ackerson's signature that gave custody of her two children to Grant Hayes for $25,000. However, an FBI handwriting specialist testified Grant likely wrote the first paragraph, and Laura likely wrote the second.
"In this case, it appears there may be two different writers between the first and second paragraphs," said FBI Handwriting Specialist Lindsey Dyn. "I was not able to form a conclusion on the signature or the date."
Investigators say Amanda and Grant killed his ex, Ackerson, and dismembered her body before dumping it in a Texas creek in 2011.
Grant is serving a life sentence for murdering Ackerson. If convicted, Amanda could face the same sentence.
The trial will resume Friday morning.