Authorities stumbled upon a key piece of evidence -- a hair in pliers in Scott Peterson's boat -- while reviewing evidence photographs in February, Modesto police Detective Al Brocchini testified.Brocchini acknowledged having called in a tip to a hot line operated by Scott Peterson's family and confirmed that he never attempted to contact Homer Maldonado or Vivian Mitchell. Both have said they saw Laci Peterson walking her dog in the La Loma neighborhood the morning of Dec. 24 -- after authorities contend that she was slain. Brocchini also said he passed information on Scott Peterson's spending habits to officials of Tradecorp, the Spain-based fertilizer firm that employed Peterson. The detective denied telling a close friend of the Petersons that he was "going to take Scott Peterson down."Police in early January tailed Scott Peterson to San Francisco Bay three times, Brocchini testified.Karen Servas, the Petersons' next-door neighbor, testified that she found the dog running free with a wet, dirty leash attached about 10:18 a.m. Christmas Eve. The timing conflicts with sightings of Laci Peterson reported by Maldonado and Mitchell.A doctor who examined Laci Peterson on Dec. 23 -- the day before she was reported missing -- said if her baby had been born then, with some assistance, he could have lived, Detective Phil Owen testified.Gloria Allred, the attorney for Fresno massage therapist Amber Frey, announced that prosecutors decided not to call Frey to the stand for the preliminary hearing. Brocchini said detectives eventually found five fishing licenses apparently belonging to Scott Peterson: a two-day license valid Dec. 23 and 24; other two-day licenses issued in August 2002, October 1999 and July 1999; and a yearlong license issued in 1994.