Sunday, June 16, 2013. Patriots tight end Aaron Hernandez, care free and on top of the world so much as anyone knew, father to an 8-month-old daughter, goes on Twitter, writes: “happy father’s day to all the great dads out there.”

Monday, June 17. Hernandez allegedly shoots to death Odin Lloyd in a North Attleboro, Mass., industrial park about a mile from his home, according to police, who charged him this week with first-degree murder.

Tuesday, June 18. Hours after allegedly killing a man, Hernandez is back on Twitter with, simply: ‘good morning.’ He has not Tweeted since.

Chilling.

Shocking.

Infuriating.

Sad beyond words.

This has been a bizarre half-year patchwork on the shake-your-head side of sports, hasn’t it? The Manti Te’o hoax. Heroic “Blade Runner” Oscar Pistorius charged with murder. Lance Armstrong verified as liar and fraud. Baseball’s latest steroids mess festering from a Miami clinic. Rutgers firing its basketball coach for abusing players. The NCAA’s corrupt bungling of the UM investigation. That’s not even including the Boston Marathon terrorist bombings that were only tangentially about sports at all.

Now, this.

A rising NFL star, aged 23, playing for a glamour team and newly signed to a five-year contract worth $40 million, throws his life away before our disbelieving eyes.

The Patriots immediately cut him after his arrest, but that and his football future suddenly are the least of Hernandez’s concerns. Now he also is being investigated as part of an unsolved double-murder from 2012, inviting one to wonder if a killer on the loose was catching passes for New England last season, playing the Dolphins twice.

The propensity of some athletes — a relative few, but far too many — to royally screw things up continues as dumbfounding.

Do these men bent on self-ruination not appreciate or understand how good they have it? How blessed and lucky they are? To be cheered as heroes and lavished with riches for … what, for catching a football? For playing a game!?

It’s strange, though. Sometimes what shocks you does not totally surprise you, and that may be the case with the situation Hernandez has fashioned for himself.

There were signs — albeit signs always seen more clearly in retrospect than in real time. If you can’t see those signs point toward murder, you can at least see them point toward trouble.

Hernandez’s father died unexpectedly from complications in hernia surgery before his senior year in high school and it changed Aaron.

“He was very, very angry,” his mother told USA Today in 2009. “He wasn’t the same kid.”

Behavior and maturity issues, including marijuana use, followed him to the University of Florida.

“I wasn’t the biggest fan of school,” he admitted once.

Off-field concerns, including some of the old homies from Connecticut he hung out with, sent up red flags in the NFL. It was why he wasn’t drafted until the fourth round.

Mrs. Hernandez’s “very, very angry” child was implicated in a shooting just this past February at Tootsie’s strip club in Miami, an episode that currently has him the subject of a civil suit.

How many NFL teams that researched Hernandez carefully before the 2010 draft were surprised by that? (Rhetorical question. Answer: Not many.)