Singer Christina Grimmie, 22, a former star of "The Voice" and a YouTube sensation, was shot Friday night as she signed autographs for fans at a merchandise table in The Plaza Live concert venue in Orlando, Florida. She had performed with the band Before You Exit earlier in the night.

"She was doing a meet-and-greet, just signing autographs and selling merchandise. This white male approached her and opened fire, striking her," said Orlando Police Chief John Mina at a news conference on Saturday. "We believe he came here to commit this crime."

Grimmie had been "critically injured" when police officers arrived at the venue shortly after the shooting. She died of her injuries at a hospital at about 3 a.m. local time Saturday, according to a police statement.

Mina said the killing was a premeditated attack by a man identified as 27-year-old Kevin Loibl of St. Petersburg, Florida. The suspect had traveled to Orlando with two handguns, several loaded magazines and a hunting knife.

Grimmie's brother, Marcus, immediately tackled Loibl, who then shot and killed himself during the struggle, police said. They credited Marcus Grimmie with preventing the gunman from hurting any of the 120 other people who were in the venue at the time.

"Her brother Marcus is a hero and possibly saved countless other lives," police said.

Mina added that unarmed security guards at the concert venue had been checking bags and purses, but that the venue had not had metal detectors.

Detectives, meanwhile, were searching Loibl's mobile phone and social media accounts in an attempt to find a motive.

Mina said the suspect did not appear to have a criminal record and there was no indication he and Grimmie knew each other, adding that it appeared Loibl may have been a deranged fan.

From YouTube to 'The Voice'

Grimmie, a native of New Jersey, rose to fame as a teenager on YouTube when she sang covers of well-known songs by artists such as Miley Cyrus, Celine Dion and Usher.

In 2014 she took part in "The Voice" TV singing competition, finishing in third place. She gained the praise of the show's hosts and a contract with Island Records.

Her manager, Brian Teefey, posted a message on Twitter following her death, asking for support for her family.

jm/cmk (AP, Reuters)