The Virginia Department of Emergency Management is organizing a second community search effort this Sunday in the ongoing investigation into the disappearance of second-year College student Hannah Graham.Volunteers will search Walnut Creek Park from 9 a.m. until 4 p.m. in two shifts, according to a VDEM statement. Due to limited parking, only the first 200 volunteers who register will be able to participate in the search. Anyone interested in participating must first sign up at www.hikeforhannah.brmrg.org. Participants will sign up for either a 9 a.m. shift or a 1 p.m. shift, or they may participate in both. Walnut Creek Park is 525 acres — including two acres of beaches — and located about 11 miles southwest of University Grounds."This location is an area of interest to the investigation and has not been fully searched," VDEM spokesperson Dawn Eischen said in an email. "We expect the volunteers to complete that area in one day."This is the second community search in the Graham investigation. The first was held Sept. 20-21 and brought in 1,250 members of the community. Volunteers do not have to have participated in training for the previous search to participate, Eischen said. Volunteers will receive a briefing upon arriving at the park and be assigned to a search team. The registration website says the second search is coming at the request of Charlottesville Police Chief Timothy Longo and on behalf of the Graham family.Graham was last seen on the Downtown Mall in the early morning hours of Saturday, Sept. 13.