Forensic experts for Los Angeles police testified Tuesday it is inconclusive whether a UCLA student was sexually assaulted before she was killed in 2015.

Ernest Park, a criminalist and DNA analyst with LAPD, said he examined samples from the body of Andrea “Andy” DelVesco, who had been killed in her apartment, which was set on fire. Park testified he did not detect any sperm or male DNA from her body, but he added the test was inconclusive because the male DNA level was above 0 but below the standard to test positive.

Alberto Medina, a former Fresno State University student, is accused of killing DelVesco and setting her apartment on fire in 2015. County prosecutors also believe Medina is responsible for two burglaries, arson and injuries to DelVesco’s dog that led her family to euthanize it.

DelVesco’s body was charred beyond identification from the fire, said Jessica Gadway, senior criminalist at the LA County Department of Medical Examiner-Coroner. Gadway said she collected a modified sexual assault kit to take DNA samples from DelVesco’s body to determine whether she was sexually assaulted. Her body was too charred to determine external signs of sexual assault, Gadway said.

Chuck Knolls, who was a detective at the time of the investigation, said he also collected a sexual assault report to document injuries on Medina’s body to see if there were signs of struggle from DelVesco. However, an analysis of the report showed he had no injuries, said Mara Landa, a registered nurse and forensic nurse examiner.

Forensic experts also examined the number and extent of sharp force injuries to DelVesco to determine the cause of death.

Matthew Miller, deputy medical examiner at the Los Angeles County Department of Medical Examiner-Coroner, said although DelVesco’s skin was charred, he was able to identify at least 19 sharp force injuries, two of which perforated both of DelVesco’s carotid arteries, major arteries that are close to the heart. Sharp force injuries include stab wounds, which are deeper, and incised wounds, which are shallower but longer, Miller said.

The cause of fire of DelVesco’s apartment on Roebling Avenue was deemed to be intentional based on evidence that there was was little damage to the floor in comparison to DelVesco’s bed, meaning the fire started above the ground, said Robert McLoud, an arson investigator.

He added the height and intensity of the fire on the bed makes him think the first flames were on the bed, in particular in a trash can on the bed, because of its unusual placement and the debris inside.

McLoud said the intact wall plugs indicated the fire did not have an electrical source, and the door into the bedroom was closed during the fire based on the burn patterns on the door.

The prosecution and defense for Medina’s trial will continue collecting testimony from witnesses Wednesday.