The prosecution is still presenting its evidence against Antolin Garcia-Torres.
"It's always a sad day this day, but we're thinking about Sierra," said Steve LaMar, the teen's father.
Today's testimony focused on the accusation that he tried to kidnap three women at Safeway's around Morgan Hill several years before Sierra's disappearance.
"What the defense wants to establish is that it's not Mr. Garcia-Torres that committed these Safeway attacks and they're saying the forensic evidence is really minimal here," said legal analyst Steven Clark.
Crime lab analyst testifying about process to look at prints on stun gun DA thinks Antolin used in attempted kidnap of women at Safeway— Janine De la Vega (@JanineDLV) March 16, 2017
During the cross-examination, the defense focused on whether the fingerprints found on the evidence was reliable or if it was possibly tainted.
RELATED: Defense gives opening remarks in Sierra LaMar murder trial
The DNA of one of the investigators was transferred on the stun gun and he testified it was embarrassing and he's not sure how that happened.
"What you'll see the defense try to do is suggest that if it wasn't done properly in the beginning, it really doesn't matter what the evidence shows at the end because there's a break in the chain.
Defense trying to prove evidence in Safeway attempt kidnappings mishandled by investigators. Attacks happened before Sierra disappeared.— Janine De la Vega (@JanineDLV) March 16, 2017
"That was the day the LaMar's life turned upside down and it's a day they can never escape," said Marc Klaas, with the Klaas kids foundation.
The trial is expected to last through April. If convicted Garcia-Torres could be sentenced to death or life in prison without parole.