FORT WORTH -- At first, James Wesley Jackson denied he had ever seen Jo Beth Marchand.But by the end of that first interview with Fort Worth homicide investigators, Jackson had conceded that he recognized Marchand, had previously helped her with groceries and had even once had sex with her.By the second interview, Jackson admitted to police that he had gone inside Marchand's apartment twice after finding her door slightly ajar while visiting a friend at the complex, stealing items and "hanging out" watching TV."I didn't kill this woman, but I was there," Jackson told Detective W.D. Paine on March 6, 2012, the day of his arrest.But Jackson said he didn't know anyone was dead inside the apartment until deciding to check out a bedroom closet and stepping on something on the floor under a comforter."When I stepped on her, I immediately knew that I was not in that closet by myself," Jackson said.Jurors watched the two taped interviews Thursday, the second day of testimony in Jackson's capital murder trial.The final taped interview is expected to be played for jurors this morning in State District Judge Scott Wisch's court.Jackson, 43, is accused of sexually assaulting and strangling Marchand, described by friends as slightly mentally challenged, while burglarizing her apartment south of downtown Fort Worth. Friends discovered Marchand's body concealed in her bedroom closet on Dec. 2, 2011.Because prosecutors have waived the death penalty, Jackson faces automatic life in prison without parole if convicted.'Is that a criminal charge?'In his second taped interview with police, Jackson told Paine that he did not have sex with Marchand as he had told Paine and Detective Jeremy Rhoden in his first interview.He said that after finding the woman dead in the closet, he spent about another 20 minutes inside the apartment before leaving.He told Paine he wiped down the television he had touched and threw away evidence of the cigarettes and drinks he had consumed in an apartment-complex bin. He said he left the apartment with black trash bags he'd filled with clothes, food and rolled change.When asked by Paine if he had had sex with Marchand's body in the 20 minutes after discovering her dead, Jackson said no.When asked if he had ejaculated near her body, Jackson paused, then asked, "Is that a criminal charge?" before saying yes. Jackson, however, denied knowing how Marchand died or how she might have suffered vaginal trauma.Strangled and beatenEarlier in the day, Dr. Marc Krouse of the Tarrant County medical examiner's office, testified that Marchand had been strangled with so much pressure "that it damaged everything all the way back to her spine."Krouse said that although he determined Marchand had died from ligature strangulation, she also had blunt trauma to her head, had been struck hard enough in the nose to fracture cartilage and had a number of bruises on her body.Krouse testified that Marchand had injuries to her vaginal area indicative of sexual assault.He said he also chemical burns on her thighs that occurred sometime after her death. "It could be almost anything. Chicken soup could probably do that," Krouse said."What about household cleaners?" asked Sheila Wynn, who is prosecuting the case along with Bryan Hoeller."Yes," Krouse replied.Witnesses have testified that a green towel found near Marchand's body was damp and smelled of household cleaner, suggesting that Marchand's killer may have tried to clean up evidence.Sundaye Lopez, a forensic scientist with the Fort Worth police crime lab, testified that swabs she tested from a rape kit were positive for blood but not seminal fluid. She testified that the absence of seminal fluid, however, does not rule out that sex occurred.Explanations, she said, could be that ejaculation did not occur, a condom was used, or cleaning was done to remove such fluids.A DNA analyst with the University of North Texas Center for Human Identification testified that Jackson could not be excluded as one or at least two minor contributors to a mixed DNA profile found on a blood-stained cushion cover.Another analyst testified that DNA from four hairs found on a blanket and one hair on a comforter matched Jackson.