A cop with the Chicago Police Department, Pat is just a regular guy who loves his city, the Bears, and his family — not necessarily in that order. He is a devoted father to Jimmy, Kenny, and Shannon, if not at times an inept one, having once brought his kids to visit a gruesome crash site to teach them not to drink and drive. After eighteen years as Eileen's affable, compliant husband, their separation leaves him a little less than prepared to handle life on his own as a single guy. Now that he's suddenly independent, Pat's going to have to learn to make his own decisions about things, whether that's how to raise his kids, or how to buy furniture for himself. The good news is that if Pat ever needs Eileen's help, he only has to take a short trip upstairs from his "divorce apartment," also known as the basement, where she will be only too happy to weigh in with her opinions.
After he and Eileen announced their divorce, Eileen claimed custody of the house, but Pat didn't have another house to move to yet. He had to live in the basement, which he called his "divorce apartment", which he lived in for all of Season 1. In the Season 2 episode, The Real Fit, Pat built a tiny house in the backyard. He moved into that house, which is where he currently lives today.
As revealed in "The Real Fit", Pat grew up in a family of six. We were introduced to his brother Dwayne, and there was mention of him having four other brothers named Sean, Paul, Mark, and Brandon. All of his brothers grew up the persue the career of becoming firefighters. Pat was the odd one out, being the only one who became a cop.
Pat was in an ambiguous relationship with Gloria, a girl who works at the Police Station with him. This relationship ended in the episode The Real Sin, when Pat waited too long to officially ask her out, and she ended up going out with another guy.