A Westchester County high school student has been sentenced to "shock probation" for stalking a 16-year-old schoolmate last year, leading to a key-theft confrontation that left the girl stabbed in a Dunkin' Donuts. She later died.

Carl Booker, along with fellow student Dominique Slack, pleaded guilty in December to felony stalking in the Jan. 10, 2018 death of Valaree Schwab. Slack was also sentenced to shock probation, which involves a six-month incarceration in Westchester County jail followed by five years' probation. 

Prosecutors have said Booker, Slack and other teenagers stalked Schwab, a classmate at New Rochelle High School, on several occasions -- and one time, it turned physical, with the group attacking Schwab on a North Avenue sidewalk.

As she was being attacked, Schwab dropped her house keys and one of the teens picked them up, authorities have said. The group went to a Dunkin' Donuts on North Avenue and Schwab, desperate to get her keys back, followed them.

She was stabbed inside the restaurant when she dried. Schwab was pronounced dead later that day. 

A third teen, Z'inah Brown, still has second-degree murder charges pending against her. Authorities allege Brown, then also 16, was the one who stabbed Schwab in the Dunkin' Donuts, ultimately to death.

Brown turned herself in hours after the police released a wanted poster. After her arrest, Brown's attorney only said his client was "doing OK" and that he had no further comment.