Karen Read's defense team is looking to build on momentum yesterday from a surprise police witness who testified that her taillight was less damaged when he helped seize it with a warrant than it appears in photos taken after it arrived at the Canton Police Department, where authorities first towed it.Taillight fragments were not found at the crime scene until later, too, and her defense's implication is that they could have been planted there.Wednesday marks the 27th day of Read's retrial on murder and other charges in the January 2022 death of her then-boyfriend, Boston Police Officer John O'Keefe.KAREN READ'S