The FBI says it's expanded its search nationwide for a 13-year-old Wisconsin girl missing since her parents were found shot to death in their home Monday morning. Authorities say Jayme Closs was in the house when her parents – 46-year-old Denise and 56-year-old James Closs – were killed. 
 
 The girl, who was ruled out as a suspect on the first day, was gone when deputies arrived. Relatives of Jayme told CBS News the front door to the house was shot in. 
 
 When officers responded minutes after a 911 call to the home in Barron, about 80 miles northeast of Minneapolis, they found no suspicious vehicles, says CBS Minnesota. 
 
 The FBI said Thursday that, "out of an abundance of caution," it was sending a digital Missing Person poster to local media partners across the country for display. 
 
 Jayme Closs, age 13, has been missing from Barron, Wisconsin, since Monday, October 15, 2018. Help the #FBI find her: https://t.co/s0fHKjY3hc pic.twitter.com/XRzoQzLxxH — FBI Most Wanted (@FBIMostWanted) October 18, 2018 
 
 More than 100 local and state FBI agents have been working on the case, and officials say hundreds of tips have come in from the community and people around the country, the station reports. 
 
 One-hundred volunteers have joined the search for Jayme, authorities said Thursday, after Barron County Sheriff Chris Fitzgerald asked for people to pitch in. 
 
 He said Wednesday investigators believe she's alive but in danger and he urged the public to continue calling in tips. 
 
 The sheriff's office posted on Facebook Thursday afternoon that so far "nothing of evidentiary value has been recovered." 
 
 She's described as standing 5-feet tall, weighing 100 pounds, with green eyes and blonde hair. ||||| A missing teenager has been added to the Federal Bureau of Investigation’s top missing persons list. Jayme Closs, a 13-year-old from Barron County, Wisconsin, was reported missing on Monday, October 15, after both of her parents were found dead inside their home. 
 
 The FBI announced on Thursday it was expanding its search for Jayme, who was described as 5 feet tall and 100 pounds, with blonde hair and green eyes. The FBI said it considered the girl “endangered.” 
 
 Police officers located the bodies of James Closs, 56, and Denise Closs, 46, at their home in Barron County on Monday, dead of apparent gunshot wounds, after a 911 call was placed. Their daughter Jayme was not in the house. Authorities had not located any suspects and had not yet determined whether the adults were targeted or whether the killings were random. The motive in the killings remained unknown, and it was not immediately clear who made the 911 call. Authorities reportedly found out whose cellphone the 911 call was dialed from but did not share the information. 
 
 Barron County Sheriff Chris Fitzgerald announced on Wednesday that autopsy results ruled the deaths homicides, and that both adults were killed by gunshot wounds. 
 
 “We believe Jayme was in the home at the time of the homicides, and we believe she’s in danger,” said Fitzgerald, according to CNN. 
 
 Hundreds of tips have poured in related to the case, but authorities still have not located Jayme. In a press release on Thursday, the Barron County Sheriff's Office said "nothing of evidentiary value has been recovered." 
 
 An extensive search was underway for the girl, with authorities and volunteers scouring Barron County for traces of the teenager. Fitzgerald said he had a "100 percent expectation that she's alive," according to CNN. 
 
 “At the end of the day, I want a 13-year-old here safe and sound,” said Fitzgerald. “That’s our goal. That’s our only goal right now.” 
 
 Anyone with information was asked to contact the Barron County Sheriff’s Office at 1-855-744-9879, their local FBI office or the nearest American embassy or consulate. 
 
 FBI ||||| (CNN) Volunteers and law enforcement combed the side of a highway on Thursday looking for evidence in the disappearance of a missing Wisconsin teenager whose parents were found dead in their home this week. 
 
 But the search along Highway 8 in Barron County, Wisconsin, didn't turn up anything of value, according to Barron County Sheriff Chris Fitzgerald. 
 
 Hours earlier, Fitzgerald asked for 100 volunteers to help in the routine search for evidence that could be related to the case as the search for Jayme Closs entered its fourth day. 
 
 The 13-year-old was likely at her family's Barron home, located on Highway 8, when her parents were shot dead, and she vanished moments later, investigators believe. Her whereabouts and safety are still in question. 
 
 "We believe Jayme was in the home at the time of the homicides and we believe she's still in danger," Fitzgerald said this week. 
 
 Thursday's search took place about 3 miles from the family's home, according to CNN affiliate WCCO 
 
 Since authorities received a cryptic 911 call and discovered the bodies of Jayme's parents in their home near the town of Barron early Monday, investigators have received more than 800 tips and have not confirmed any credible sightings of the girl. 
 
 But the sheriff said he has a "100% expectation that she's alive." 
 
 #FBIMilwaukee needs your help, as the search continues to bring home 13 year old Jayme Closs, now missing & endangered after her parents were found dead in their home in Barron, WI early this week. Call the tip line 1-855-744-3879.#FindJayme pic.twitter.com/rNELlQKJb6 — FBI Milwaukee (@FBIMilwaukee) October 17, 2018 
 
 An Amber Alert was issued Monday for Jayme and several law enforcement agencies have joined the search. 
 
 Motive in parents' death is unclear 
 
 Deputies are also trying to solve the killings of Jayme's parents, James Closs, 56, and Denise Closs, 46, in the small city of Barron. 
 
 During a 911 call shortly before 1 a.m. Monday, the dispatcher heard a disturbance in the background. But no one spoke directly to the dispatcher, Fitzgerald said. 
 
 When deputes arrived to the home less than four minutes later, Fitzgerald said, no one was in sight and no vehicles were in the immediate area. 
 
 Closs' parents were shot and their deaths have been ruled homicides, Fitzgerald said Wednesday. No gun was found at the scene, he said. 
 
 It's not clear how long James and Denise Closs had been dead when their bodies were discovered Monday. 
 
 On HLN's "Crime & Justice" Wednesday night, Fitzgerald told host Ashleigh Banfield that deputies had recovered the cell phone from which the 911 call was made. 
 
 Fitzgerald said additional agencies, including the FBI, are involved. "They are the experts in breaking down 911 tapes, looking at our phones, and taking care of all evidence in that manner," he said. 
 
 Authorities said they have determined whose cell phone the call came from, but declined to identify the owner. 
 
 Investigators also believe Jayme was at home during the shooting based on details from the 911 call and evidence from the home. 
 
 "Is it a random attack or a targeted attack? I don't know that answer," Fitzgerald told reporters. "That's why those leads are so important." 
 
 Joan Smrekar, who lives next door to the Closs home, told Banfield she heard two shots a couple of seconds apart just after 12:30 a.m. Monday. 
 
 "It was just, 'bang' and 'bang,'" Smrekar said. 
 
 Relatives wait in agony 
 
 Seara Closs said she wishes she were the one endangered, not her cousin Jayme. Seara wrote an open letter to Jayme on Facebook. 
 
 "I'm going thru our family pictures, worrying sick about you :( wishing we could trade places just to get you home and out of harms way," Seara Closs posted 
 
 In her post, Seara reminded her cousin that her family -- including her slain parents -- love her dearly. 
 
 "Grandpa Jim (James) Closs, your Momma Bear, Denise Closs and your very own night [in] shinning armor, your Daddyo Jim JR Closs ... love all of you!" Seara Closs wrote. 
 
 Authorities said they don't believe Jayme Closs ran away. 
 
 Barron Area School District administrator Diane Tremblay said Jayme, a member of her school's cross-country team, is a "sweet girl who is a loyal friend and loves to dance." 
 
 During a recent school assignment, Jayme was asked what she would do with $1 million, Tremblay said. Jayme wrote that she would "feed the hungry and give the rest to the poor." 
 
 Both James and Denise Closs were long-time employees of the Jennie-O Turkey Store in Barron, Jennie-O's parent company Hormel said. 
 
 "Our thoughts are with the Closs family and the entire Barron community," said a statement from Jennie-O Turkey Store officials. 
 
 "This is a difficult time for our entire team and we are mourning this loss and are still processing this terrible tragedy. We are also hopeful for the safe return of their daughter, Jayme, and are keeping her and the Closs family in our thoughts." 
 
 Jayme Closs is 5 feet tall, weighs 100 pounds and has green eyes and blond or strawberry blond hair, the sheriff's department said. Anyone with information can call the tip line at 1-855-744-3879. 
 
 Correction: A prior version of this story incorrectly spelled the missing girl's last name.
– "Every second counts" in the search for Jayme Closs, and authorities say they've so far received about 800 tips on the disappearance of the Wisconsin teen. The 5-foot-tall 13-year-old with strawberry-blond hair and green eyes was found to be missing early Monday when cops responded to a 911 call at her Barron home; her parents were found there shot to death. In addition to hundreds of tips being called in, USA Today notes that a team of 100 volunteers, recruited on Facebook by Barron County Sheriff Chris Fitzgerald, has been scouring the area in a "routine search for articles of evidentiary value." The hunt for Jayme—who Fitzgerald seems certain is still alive, per CNN—isn't just in Barron: CBS News and Newsweek report the FBI has expanded the search nationwide, with the agency placing Jayme on its top missing-persons list and blasting out a missing-persons poster "out of an abundance of caution" to media across the country. More than 100 local and state FBI agents are said to be helping to find her. "At the end of the day, I want a 13-year-old here safe and sound," Fitzgerald said Wednesday. "That's our goal. That's our only goal right now." (So far, not much has turned up.)