MINNEAPOLIS -- A 32-year-old man has died after an officer-involved shooting Wednesday night in the St. Paul suburb of Falcon Heights, authorities say.

Police in St. Anthony, Minnesota confirmed that the man was dead. Philando Castile's mother told CBS Minnesota he died at Hennepin County Medical Center.Castile's family and friends gathered at the hospital and were joined by Nekima Levy-Pounds, president of the Minneapolis chapter of the NAACP. An estimated 200 people were gathered at the shooting site at 1:30 a.m. local time, CBS Minnesota reports, adding that the crowd had pretty much dispersed an hour later.St. Anthony Police said in a news release that officers pulled over a vehicle at about 9 p.m. They said "shots were fired" during the traffic stop, and a handgun was recovered at the scene.

Castile's girlfriend, Diamond Reynolds (also known as Lavish Reynolds), and her young daughter were in the car, CBS Minnesota reports.

Reynolds was in custody Wednesday night. There was no initial word on why she was being held.

The incident comes a day after two white police officers in Baton Rouge, Louisiana were involved in the fatal shooting of a black man outside a convenience store.

A video taken by Reynolds that was circulating on Facebook, briefly removed but then restored (with a warning about its graphic content), appears to show the aftermath of the Minnesota shooting.

In the video, in the car, she says as Castile was reaching for his wallet, he told officers he had a firearm in his possession, and a conceal-and-carry permit.

Reynolds says an officer then shot her boyfriend four times.

The officer in the video, who appears to be very emotional, at one point screams, "I told him not to reach for it! I told him to get his hand out."

Reynolds, who is very composed, tells the officer, "You told him to get his I.D., sir, his driver's license."

She pans the cellphone camera over Castile, who is covered in blood.

"Oh my God, please don't tell me he's dead. Please don't tell me my boyfriend just went like that," Reynolds says.

The officer, whose gun is drawn the entire time, pointing into the open passenger side front window, tells Reynolds to "keep your hands where they are."

"Yes I will, sir, I'll keep my hands where they are," she assures him.

Reynolds is then told to get out of the car. Her cellphone shows several officers with guns drawn, and one is holding her daughter.

Valerie Castile tells CBS Minnesota her son was a cafeteria supervisor at J.J. Hill Montessori School in St. Paul.

The Minnesota Bureau of Criminal Apprehension is investigating.Sgt. Jon Mangseth, St. Anthony Police's interim chief, told reporters he wasn't aware of the Facebook video or its content.

"[We haven't had an] officer-involved shooting in, you know, 30 years or more. I'd have to go back in the history books, to tell you the truth," Mangseth said.

He later told reporters in a very brief news conference early Thursday morning that the officer who shot Castile has been placed on standard paid administrative leave.

The St. Anthony Police Department provides police services for the neighboring cities of Falcon Heights and Lauderdale.