Mackenzie Cowell was last seen alive on an afternoon in February. The 17-year-old high school senior from Wenatchee was caught on surveillance tape getting into her car as she left a class at her cosmetology school. Now, months after a homeowner found Cowell’s body lying on the banks of the Columbia River, police in her small hometown say they’re “cautiously optimistic” about a new set of leads.Mackenzie Cowell was a popular member of the dance team before she went missing.The Wenatchee World

reports that investigators are focused on a hairpin turn above Crescent Bar. An earlier tip had suggested that Cowell had been taken there before being murdered.Cowell’s car was discovered abandoned in a remote part of Chelan County. Her purse and a change of clothes were found locked inside and one set of footprints was discovered leading away from the car.After her body was found, police were flooded with tips. And local gun stores reported a surge in sales as freaked-out residents stocked up on weapons and ammo.The last person to hear from Cowell was her boyfriend, who received a text the afternoon she disappeared asking, “Hey, what’s up?” A 20-person investigative team, including members of the F.B.I., has been at work on the Cowell case for months. But despite checking more than 400 tips and conducting more than 700 interviews, no arrests have been made and no suspects announced.