By Nora Naughton and Rebecca Davis O'Brien

INDIANAPOLIS -- Vigils sprung up across the city Saturday for the eight victims of a mass shooting, as law-enforcement officials in the city continued to investigate the shooter's motives.

Brandon Hole, a 19-year-old former employee of FedEx Corp., killed eight people and wounded several others before taking his own life at the company's ground facility here Thursday night, police said. Mr. Hole had been temporarily committed last year for mental-health problems, and the Federal Bureau of Investigation also confiscated a gun from him last year, authorities said.

Late Friday, police identified those who died in the shooting: Matthew Alexander, 32 years old; Samaria Blackwell, 19; Amarjeet Kaur Johal, 66; Jasvinder Kaur, 50; Sardar Jaswinder Singh, 68; Amarjit Sekhon, 48; Karli Smith, 19; and John Weisert, 74.

Among those killed were four members of the Sikh community. The Sikh Coalition, a national advocacy group, said it was in touch with law-enforcement and government officials, pushing for a thorough investigation into the shooter's motive and changes that would protect minority communities.

As with the shootings last month in Atlanta -- in which six of the eight victims were women of Asian descent -- the preponderance of Sikh victims in Thursday's shooting raised questions about whether the attack was motivated by ethnic or religious animus.

"We fully expect that authorities should and will conduct a full investigation -- including the possibility of bias as a factor," the coalition said in a statement.

"We are not ruling out any motive at this time," Paul Keenan, special agent in charge of the FBI's Indianapolis office, said in a statement. The Indianapolis Metropolitan Police Department is leading the investigation, he said.

"The FBI continues to work with IMPD and other law enforcement partners to find a motive for this senseless act of violence, and will be meticulous and thorough in our investigation and devote as much time as needed to find answers for the victims' families," Mr. Keenan said.

At least three vigils were planned in the area Saturday, including a candlelight vigil at 7 p.m. at Krannert Park.

Saturday afternoon, a few dozen people gathered for a prayer vigil in the parking lot of the Olivet Missionary Baptist church on the west side of Indianapolis. Among the attendees were members of the gun-control activist group Moms Demand Action, a member of Indiana's Asian-American Alliance and a handful of Indianapolis mothers who have recently lost children or family members to gun violence.

Kendra Ford said her 21-year-old son and her two nephews died in a shooting related to a robbery in February last year, and she still recalls waiting to find out if her son had died. Those feelings were rekindled Thursday night during the shooting at the FedEx facility, just down the road from where Ms. Ford works sorting mail for the post office.

Ms. Ford could see the police lights and hear the sirens from her office. On her way home, she said, she thought of the families waiting to find out about their loved ones and began to cry behind the wheel.

"It's just so hurtful knowing that these people had to go through this, and those men and women were just at work," Ms. Ford said. On Friday, she said she left work early because she was afraid of another attack.

"I just could not be there thinking, 'What if somebody walked in here?'" she said.

Rupal Thanawala, president of the Asian-American Alliance, wiped away tears during a prayer for the victims of the shooting at the start of the vigil. Afterward, she said the Asian American community is very "hurt and fearful" at the moment, noting that she doesn't always wear her bindi in public when she feels she must blend in.

"Hate crimes are not new to Asians," said Ms. Thanawala, a 25 year Indianapolis resident originally from Mumbai. "This is the way we have been living for years now."

Marion County Prosecutor Ryan Mears, a Democrat whose office oversees Indianapolis, called for a "thorough investigation" into the shooting and said the state needs a hate crime law. "One of the tools I need is a hate crime law, and this incident just underscores that," he said in an interview.

Indiana is one of five states that doesn't have a criminal hate crime statute. In 2019, the governor signed legislation allowing judges to impose longer sentences for crimes motivated by bias, but the law has been criticized by Democrats and civil-rights organizations for being discretionary and for not listing protected classes.

K.P. Singh, a local designer and longtime member of Indianapolis's Sikh community, said he was working with faith leaders to organize a service Sunday at the Sikh Satsang of Indianapolis that would honor all the victims of Thursday's attack.

"I hope we can come together and start thinking about what steps we can take to keep all of our families, neighborhoods, schools and workplaces safe -- not a month or a year from now, but right now," Mr. Singh said.

The Sikh community has been growing in Indianapolis since the late 1990s, according to a history of the Sikh Satsang of Indianapolis posted on a website for Butler University, a private college located in Indianapolis. The local congregation has grown from 50 to more than 1,000 community members in the last decade, most of whom are from the Punjab region on the border of India and Pakistan, the website says.

Sikhism is a monotheistic religion founded in India in the 1400s. Because some Sikhs wear turbans they sometimes are confused with Muslims, and some Sikhs have been the targets for violence or harassment in the aftermath of the Sept. 11, 2001, attacks.

In 2012, a white supremacist attacked a Sikh temple in Oak Creek, Wis., killing six people and then himself. The incident is still raw among Sikhs in the U.S.

Thursday night's attack was the fourth public mass shooting in the U.S. in which four or more people were killed this year, according to the Violence Project, a mass shooting database maintained by two university professors. When domestic violence and gang-related attacks are added, there have been a total of 11 shootings in which four or more people were killed this year, according to the Violence Project.

Saturday afternoon, on the other side of the city from the FedEx facility where the shooting took place, gun enthusiasts gathered at a gun and knife show at the Indiana State Fairgrounds. Some said they were concerned that Mr. Hole had a gun after being investigated previously.

"I absolutely believe in background checks, and they should be stronger, " said 24-year-old Christian Ritchey of Avon, Ind., as he walked out of the Indy 1500 Gun and Knife Show.

Another attendee Dr. Leo D'Ambrosio said he is more concerned about access to mental-health care.

"It's far more important to make mental-health care accessible to all Americans than any form of gun control," Dr. D'Ambrosio said.

Write to Nora Naughton at Nora.Naughton@wsj.com and Rebecca Davis O'Brien at Rebecca.OBrien@wsj.com

Corrections & Amplifications

This story was corrected at 11:06 p.m. ET to fix the misstated name of the event. It is The Indy 1500 Gun & Knife Show which was held Saturday, not the Indy 500 Gun & Knife Show. In addition, Rupal Thanawala is a 25-year Indianapolis resident originally from Mumbai, not 25 years old.

(END) Dow Jones Newswires

04-17-21 1745ET