WHEN SOMEONE'S living under your roof, it changes things.

So, when our nephew moved in to save money as he finishes his last year at Drexel University, I found myself fretting more and more about his safety. I hate that I do this, but I nag him not to wear his dark hoodie over his head for fear of attracting negative attention.

I worry most that he might be robbed on the subway or be approached by a thug who takes him for an easy mark. But I also am deeply concerned that he might be unfairly profiled by law enforcement. Where we live, there aren't many 6-foot, 5-inch tall, young black men walking around at night carrying backpacks, as he's been known to do. So, yes, I'm nervous for him for a lot of reasons. Racism is real.

For proof, look no further than the online comments about Minnesota's Philando Castile or any of the other black males killed by police in recent months. The last couple of days, the online chatter has been particularly vile in the aftermath of not one but two controversial police killings involving black men.

In the most recent incident (caution: graphic footage), an eyewitness used the popular feature Facebook Live to livestream the disturbing aftermath of a deadly encounter outside Minneapolis. On the video, Castile, a beloved school cafeteria supervisor, lies helpless as the life eeks out of him. His girlfriend, Diamond Reynolds, calmly tells the story into her smartphone that she and her boyfriend were pulled over for driving with a malfunctioning taillight. She claims Castile had informed the officer that he had a gun and that as Castile did as instructed and reached to get his license, the cop shot him four times.

It's really awful. Castile's white T-shirt is stained with blood and his body slumped over as Reynolds explains, "They just killed my boyfriend ... Oh my God, please don't tell me he's dead. Please don't tell me my boyfriend's dead." Just outside the passenger-side window, a police officer's outstretched arms can be seen pointing a revolver inside where Castile lays dying and Reynolds is recording.

The officer yells, "I told him not to reach for it. I told him to get his hand (up)." Reynolds replies, "You told him to get his ID sir, his driver's license. Oh my God, don't tell me he's dead. Please don't tell me my boyfriend just went like that."

Castile later was pronounced dead at a local hospital.

"Would this have happened if the driver were white, if the passengers were white," asked Minnesota Gov. Mark Dayton on Thursday. "I don't think it would have."

I don't think it would have either. According to a recent study by the Guardian newspaper, young black men were nine times more likely than other Americans to be killed by police officers in 2015.

Just a day earlier, the nation's attention was riveted onto Baton Rouge, La., where another black man, Alton Sterling, was fatally shot by police early Tuesday after they accosted him while he was selling CDs outside a convenience store.

Videos show the police holding him on the ground before shooting him, stunning a nation already shell-shocked by such violent encounters. The part of that story that got me the most was listening to the wails of Sterling's 15-year-old son crying for his daddy during a televised news conference after the shooting.

In the Minnesota video, you hear the voice of Reynolds' 4-year-old trying to comfort her mother who wails loudly and prays that her fiance doesn't die. It's heartbreaking to see that baby's sweet face and know her life will forever be touched by the horror she's just witnessed.

"My son was a law-abiding citizen and he did nothing wrong. He had a permit to carry," his mother Valerie Castile told CNN Thursday. "They took a very good person ... He's not a gang-banger. He's not a thug."

Not that it mattered.

Two days. Two black men. Bloody videos. More devastated families. More videotaped proof of things that black people have been saying for years.

"I have a fear when my sons leave out. I have a fear when a cop pulls up behind me," Chuck Herndon, a father of two teen-aged boys in West Oak Lane, told me Thursday night. "It shouldn't be that way. I don't know how we fix it, but it shouldn't be that way."

On Twitter: @JeniceAmstrong