Stalker received negative reviews from critics at the aggregator site Rotten Tomatoes. There, critic comments include, "[it is] chock full of perverted subjects and ugly storylines, making it hard to watch even for those who like to watch." Maureen Ryan of The Huffington Post called it "exploitative, misogynist trash". At Metacritic, the series premiere garnered a score of 17 out of 100, based on the opinions of 24 critics. The show also received negative reviews from Variety, USA Today, and The A.V. Club
Detective Jack Larsen, relocating from New York, arrives for his first day on the job working for Lieutenant Beth Davis with the elite TAU team in Los Angeles. The team tackles the case of a teenage girl who is stalked while babysitting her 7-year old brother, and a college student who is charged with assault but later says he was defending himself from harrassment by a former roommate he had thrown out. Elsewhere, Jack himself spies on a mother and her child, later revealed to be his ex-wife, Deputy D.A. Amanda Taylor, and his son.
Hannah is babysitting her 7-year old brother, Thomas, and appears to be the victim of a stalker. Early evidence leads the team to a man named Barnes, who is a registered sex offender. While Barnes has several photos of Hannah, it later becomes clear that he did nothing more. The TAU acts on further clues that lead them to a neighboring woman who lost a son about Thomas' age, meaning Thomas was the intended target instead of Hannah. Near the end of the episode, Amanda gives Jack a stern warning to leave L.A. within two weeks or she will reveal a damaging secret from his past.