He is portrayed by Andy Samberg.
Jake is extremely intelligent and calculative, but this factor is dwarfed by his more comedic factors: he is incredibly immature, childish, laid-back, carefree and wisecracking. He has excellent detective skills, and Terry Jeffords considers him the best under his command. Jake revels in catching criminals and solving puzzles, and proves himself to be great at doing this on numerous occasions. He does admit that he takes his job seriously - he thinks that all that matters is putting away the bad guys, and is otherwise ignorant or lazy to any other activities in his job. He loves movies and games - he frequently displays his love for the Die Hard film series, and enjoys giving himself flashy nicknames and elaborate backstories as if he were the character in an 80s action film.
He has a sarcastic, wisecracking, childlike sense of humor, often joking even in the most serious of situations. At first, Jake hates his new precinct captain - Ray Holt - because of the man's serious, pragmatic personality, and the fact that he does not respond well to Jake's quirks and jokes. However, he comes to see the man as a father figure and the two make an incredible team. Jake is a good man, empathetic and striving to help people he cares about, and is often deeply affected if he feels he's failed at protecting people in the line of duty.
Jake, throughout the series, comes up with various make-belief names for himself when working:
- Bart Barley - a happy-go-lucky vegetarian who hates violence against animals.
- Rex Buckingham - British secret agent, ballistics expert and ladies' man.
- Dick Kovak - An American cop who was double-crossed and left for dead.
Jake has had a number of crushes over the years:
- Jenny Gildenhorn - his school crush who dumped him at his Bar Mitzva for Eddie Fung.
- Amy Santiago - his adulthood crush: he and Amy are constantly at each other's throats competitively, but Jake has been shown cryptically, many times, to have a crush on her.