Phil Spector's blood was not found on the gun used to kill the actress he is accused of murdering, a court has heard. Forensic expert Steve Renteria testified only Lana Clarkson's DNA was discovered on the .38-caliber revolver found at her feet at the music producer's Los Angeles mansion on February 3, 2003. A large smear of blood on a staircase banister next to where Clarkson's body was found slumped in a chair also only showed her DNA. Renteria explained, "There could have been trace cells from another donor", but they could have been overwhelmed by the large amount of Clarkson's blood. Spector's lawyer Christopher Plourd also highlighted the defendant's DNA was not detected on the bullets found in the gun. Prosecution lawyer Alan Jackson pushed the theory other people could have come into contact with the weapon. He asked the witness: "Just because Lana Clarkson was the sole donor (of DNA) that doesn't mean that nobody else on Earth came in contact with those things?"Renteria replied: "Correct. It all has to do with the amount of cells present."The forensic expert also told the jury the unexpected absence of blood spray on the wall or carpet near Clarkson's body suggested something, or someone,in front of her could have blocked it. Spector's defence team claim Clarkson, 40, accidentally committed suicide by shooting herself in the mouth.If the 67-year-old producer is found guilty of murder, he faces between 15 years to life in prison.