Impostor by Susanne Winnacker (review)

As one of a new class of human called Variants, Tessa was born with the remarkable ability to transform her appearance into a replica of anyone she touches. Now, after two years in a sheltered government school with her fellow Variant teens, she's being sent on her first mission: to hunt a serial killer on the loose in a small Oregon town by impersonating his latest teenage victim, who has seemingly survived. Tessa goes undercover as the popular Madison but finds herself distracted by gorgeous fellow operative Alec and by the challenge of living another girl's life, complete with adoring, overprotective parents, a cute but nosy twin brother, and an ex-boyfriend who just won't let go. Soon, though, she finds herself enjoying Madison's life a little too much, putting her mission and her life at risk as she tracks a murderer who may just have powers like her own. Comparisons to the popular X-Men are unavoidable, and the novel covers a lot of familiar mutant-superhero ground, but the addition of the serial-murder investigation element gives it a fresh and inventive feel. The novel begins somewhat slowly, but once the characters start their actual investigation, the action picks up and the strongly written mystery component takes center stage. A good number of possible suspects and well-played red herrings make the eventual unmasking of the villain effectively surprising, and the case's solution unearths unexpected secrets; those unresolved plot threads, along with Tessa's unresolved romantic woes and the revelation of new Variants, provide fodder for expected sequels.