John Augustine O'Shea

The Rookie is an American police procedural television series created by Alexi Hawley for ABC. The series stars Nathan Fillion, Alyssa Diaz, Richard T. Jones, Titus Makin Jr., Mercedes Mason, Melissa O’Neil, Eric Winter, Afton Williamson, Mekia Cox, Shawn Ashmore, Jenna Dewan, Tru Valentino, Lisseth Chavez, and Deric Augustine. It follows John Nolan, a man in his 40s, who becomes the oldest rookie at the Los Angeles Police Department (LAPD). It is based on real-life LAPD officer William Norcross, who moved to Los Angeles in 2015 and joined the department in his mid-40s.

Adapted from the Wikipedia article on The Rookie.