AMNA NAWAZ: Good evening, and welcome to the "NewsHour."

A spate of Saturday night gun violence has left more American families grieving.

Police in two states are imploring people to come forward with information on the shooters.

GEOFF BENNETT: In Dadeville, Alabama, a gunman killed four people at a birthday party.

And, in Louisville, Kentucky, two people died when someone fired into a crowd at a public park.

We start tonight in Alabama, where authorities have yet to release many details or name a suspect.

MAN: To my young people out there, I want you to know that you are not going through this by yourself.

GEOFF BENNETT: Another community in mourning after four people were killed and at least 15 teenagers were shot when gunfire broke out Saturday night during a sweet 16 birthday party in the small town of Dadeville.

Bre Hutchinson is one of the many victims, now recovering.

BRE HUTCHINSON, Shooting Victim: I grabbed on to somebody.

I don't know who.

And I was yelling for help.

And nobody would help me, so I had to like, gain my strength and to walk outside after being shot.

GEOFF BENNETT: A GoFundMe account has been set up to help victims cover their medical expenses and for the families who now have to make funeral arrangements.

Dadeville police have refused to provide many details about the case, but they are asking members of the community for help.

SGT.

JEREMY BURKETT (Alabama Law Enforcement Agency): If you are at home right now or you know somebody that has any information about what occurred last night, I cannot stress this enough, ever how minor you think it is, we absolutely need you to share it.

GEOFF BENNETT: A county coroner today identified the four people who died in Saturday's shooting as 23-year-old Corbin Dahmontrey Holston, 19-year-old Marsiah Emmanuel Collins, 17-year-old Shaunkivia Nicole Smith, and 18-year-old Philstavious Dowdell.

Dowdell was at the party celebrating his sister's 16th birthday, and committed to play football at Jacksonville State University this fall.

Dadeville High School Football coach Roger McDonald.

ROGER MCDONALD, Dadeville High School Football Coach: We went undefeated regular season and made it to the playoffs three years in a row, and he was a big part of that.

He was just a leader and, as far as his ability, just an electrifying player, but just a special kid, always smiling, you know, "Yes sir, no sir, thank you," well-respected, just everything you want out of a teammate or a player.

GEOFF BENNETT: According to the Gun Violence Archive, Dadeville marks the country's 15th shooting this year where four or more people have died.

Today, a bipartisan group of 162 U.S. mayors sent a letter to Congress demanding gun safety legislation, asking the question :"How many children must die, how many adults must die before our nation takes action to reduce gun violence?"

AMNA NAWAZ: Anger also grew this weekend over a recent shooting in Kansas City, Missouri, where a Black teenager was shot after showing up at the wrong House.

Residents are calling on police to charge the shooter.

GEOFF BENNETT: Our communities correspondent in Missouri, Gabrielle Hays, has the story.

PROTESTERS": Justice for Ralph!

GABRIELLE HAYS: Outrage and sorrow filled the streets of Kansas City Sunday morning, as America learned the name of yet another blank teenager on a growing list of those who've been shot, Ralph Yarl.

The 16-year-old high school junior was hospitalized Thursday night after being shot in the head while trying to pick up his younger siblings.

Police say Yarl mistakenly knocked on the wrong door and was shot there twice in the head and in the arm.

Yarl is now in stable condition, but with a life-threatening injury.

He was released from the hospital and is now recovering at home, his father told a local newspaper.

His aunt joined protesters yesterday.

WOMAN: My nephew is alive and he is healing.

It is not the story that that individual intended for us to tell.

GABRIELLE HAYS: Police have not yet publicly identified who shot Yarl, but the homeowner was taken into custody on Thursday and placed on a 24-hour hold.

He was then released with no charges yet pending further investigation.

They are looking into whether the shooter was protected by Missouri's stand your ground laws, which allow for the deadly use of force in self-defense.

STACEY GRAVES, Kansas City, Missouri, Police Chief: We recognize our frustration this can cause an entire criminal justice process.

The women and men of the Kansas City Police Department are working as expeditiously and as thoroughly as we can.

GABRIELLE HAYS: Police have not yet shared the shooter's race, but civil rights attorney Ben Crump, representing the Yarl family, says he is white.

In a statement released today, Crump questioned the police's decision to release the suspect, calling him armed and dangerous.

The shooting has deepened already existing wounds in Kansas City, which organizers say has a long history of police distrust.

DEE PORTER, The People's Coalition : We are not getting feedback, and especially if it's a person of color.

That is an issue.

And it's a constant issue with Kansas City Police Department and people of color in this community, Northland, Midtown, all of Kansas City.

It's like a slap in the face.

It's disrespectful.

It literally shows us what you think about our lives.

GABRIELLE HAYS: Kansas City's Mayor Quinton Lucas says he's been in touch with the family.

QUINTON LUCAS (D), Mayor of Kansas City, Missouri: We're working hard to uphold the principles of justice in this community and to make sure that there's fairness throughout.

GABRIELLE HAYS: A GoFundMe started by Yarl's aunt described him as academically driven and musical as the section leader in his marching band.

She says he has aspirations to attend Texas A&M and major in chemical engineering.

For the "PBS NewsHour," I'm Gabrielle Hays.