The Worst Thing Danny Reagan Ever Did On Blue Bloods
The Reagan family on Blue Bloods has done a lot of good for New York City. Since they all work in various levels of law enforcement, they collaborate together to solve crimes and bring bad guys to justice. They may not always see eye-to-eye, but at the end of the day, all the Reagans have a singular goal in mind, guided along the way by their collective Catholic faith, as exemplified in every family dinner scene.
None of them are bad people, but no one's perfect. The Reagans have certainly made their fair share of mistakes over the years, and that's especially true with Danny (Donnie Wahlberg). He's done some things over the years you wouldn't exactly expect a cop to do, all the more so considering he's a veteran of the force and not a rookie. From Danny holding his gun incorrectly to not giving enough attention to his family, there are plenty of areas where he could improve. But there's one egregious mistake we just can't overlook that really exemplifies how he sometimes just ... doesn't think.
Danny traumatized his niece by accidentally showing her a dead body
Being a detective can be a grisly line of work. You never know what you might see, which is why police departments generally don't have Bring Your Kid to Work Days. Apparently, Danny never got the memo, as demonstrated in the season 1 episode "Age of Innocence," where he takes his 14-year-old niece, Nicky (Sami Gayle), for a ride-along to a crime scene. Danny's reluctant at first, but Nicky keeps pleading so he eventually relents. That's really his first mistake right there; he's the adult, and she's a child. He needed to put his foot down and not try to come across as the "cool" uncle.
When they arrive at the scene, Danny tells Nicky to stay in the vehicle, but what he seems to not be aware of is that teenagers aren't exactly the best at following directions. At the very least, it seems like Danny should've given Nicky more information about what it is they'd likely be seeing so that she knows to stay put. Unless Danny could've made sure there was no way for Nicky to leave the car, he shouldn't have left her unattended. This leads to Nicky wandering to the crime scene where she looks at a dead body, resulting in nightmares.
It's a traumatic experience, and Nicky's mother, Erin (Bridget Moynahan), rightfully chews Danny out for it afterward. There were plenty of moments where he could've made a better decision but didn't for whatever reason. It's a major lapse in judgment, and we're assuming no other underage members of the Reagan family got to ride with him after that. Fortunately, Nicky seems to have moved past the incident, graduating from Columbia University and moving on to a great career in future seasons.