The gunman who shot and killed a singer who rose to fame after appearing on "The Voice" traveled to Orlando specifically to attack her, authorities said Saturday.

Orlando Police Chief John Mina said at a news conference that the suspect, identified as a 21-year-old white male, didn't appear to know Christina Grimmie personally. He may have been a deranged fan, although the motive was still unknown.

Grimmie was shot to death after giving a concert in Orlando on Friday night. She died early Saturday.

The 22-year-old singer from New Jersey finished third during season six of NBC's "The Voice" in 2014, competing on the team of Maroon 5 star Adam Levine. She began amassing a following on YouTube as a teenager, gripping online viewers with her powerful renditions of hit songs. Her videos on YouTube have garnered millions of views.

In an earlier statement, police said Grimmie had performed with the band Before You Exit at The Plaza Live in Orlando. The concert ended around 10 p.m., and Grimmie was shot as she signed autographs for fans at a merchandise table.

Grimmie's brother immediately tackled the gunman, who then shot and killed himself during the struggle, police said. They credited the singer's brother with preventing the gunman from hurting others.

Sgt. Wanda Miglio said that about 60 to 100 people were in attendance, though only a handful remained when the shooting happened.

Miglio said she did not know what security was like at the venue, or how the shooter got two guns inside. She also said she did not know if off-duty officers were working the concert.

"It was just a casual event," she said.

Grimmie had posted a video of herself shortly before the concert was scheduled to begin, encouraging fans to come see her perform.

Growing up in South Jersey

Grimmie attended Bethel Baptist Christian School in Cherry Hill, where she met one of her two best friends, Sarah Luebkemann, when the two were 5 in kindergarten.

In a 2014 interview, Luebkemann, told the Inquirer: "I think she knocked over my crayons or I knocked over hers. We've been best friends ever since."

Luebkemann, now 22, was grieving in her family's Marlton home after learning of Grimmie's death and didn't want to talk to anyone, her father, Bill Luebkemann, 59, said Saturday morning.

"It's a tragic and senseless loss," Bill Luebkemann said. "My daughter was Christina's best friend since kindergarten. We're shocked and saddened. What more can you say?"

He said his daughter, Grimmie, and another friend, Lauren Longo, were all best friends.

"The three of them were like triplets," he said.

Bill Luebkemann said he was not aware of any gathering for Grimmie taking place on Saturday in South Jersey.

Grimmie attended Marlton Middle and Cherokee High School through her sophomore year, when she left to go on tour with Selena Gomez. She moved to Los Angeles in December 2012 but still has deep ties to the area - and it to her.

The Philadelphia Music Alliance said in a statement Saturday that Grimmie was back in Philadelphia to perform at the Fillmore, at 29 East Allen Street in Fishtown, just two weeks ago for her hometown kickoff as a special guest on Before You Exit's "All The Lights" tour. She performed on Sunday, May 29.

"We are horrified and deeply saddened over the unconscionable murder last night of Christina Grimmie. She was poised to be one of the Philadelphia area's next global music ambassadors, but her star shined all too briefly," PMN Board Chairman Alan Rubens said in the statement. "Christina was struck down at a terribly young age, doing what she loved best. We're extremely proud to have called her our own, and she will not be forgotten. We extend our heartfelt condolences to her family, friends, and fans as we cherish her memory."

Inquirer staff writer Julie Shaw contributed to this report.