On May 18, 2009, 21-year-old Cambridge resident Justin Cosby was shot and killed in a Harvard residence hall. The violent murder at the ivy league institution made national headlines and resulted in a life sentence for the man convicted of Cosby’s murder.

Though Cosby’s mother, Denise, had fought for the harshest possible sentence for her son’s killer, she says nothing could take away the pain of losing her 21-year-old son.

“The shock and sadness of his death hit me like a lightning bolt,” she said. “He was my only son and youngest child.”

Denise Cosby spoke Monday at a virtual ceremony marking the beginning of Survivors of Homicide Victims Awareness Month, an annual commemoration focused on honoring victims and helping their loved ones, like Denise Cosby.

“I promised my son that I will spend my time remembering, laughing and helping other mothers who have lost their child or children and are struggling to get back on track,” she told a small group at Monday’s virtual meeting. “Having the opportunity to speak publicly and connect with others has helped me start my journey towards healing and transform my pain into purpose.”

The remembrance event, which started in 2000, is powered by Clementina Chéry and the Louis D. Brown Peace Institute, named after Chéry's son, who was shot and killed in 1993 at the age of 15. The committee of survivors who first organized the month of remembrance chose Nov. 20 through Dec. 20 to provide extra support for loved ones around the holidays, which tends to be a particularly difficult time. During the month of events, the Louis D. Brown Peace Institute hosts opening and closing ceremonies, vigils, support groups, meetings and potluck gatherings.

“We are more than our trauma,” Clementina Chéry said during Monday’s meeting. “We are creating our own network. We are creating our own space. We are contributing to betterment, to healing, to peace. We are transforming the way society responds to families of murdered victims.”

Since its inception in Massachusetts more than two decades ago, a handful of other states have moved to formally observe the monthlong commemoration. In August, Rep. Ayanna Pressley introduced a resolution to formally designate a National Survivors of Homicide Victims Awareness Month on a national scale.

“From grief counseling to bereavement leave to financial assistance, congressional intent is a powerful thing,” Pressley said at Monday’s ceremony. “This resolution expresses that Congress sees you. We hear you, and we've committed to making the investments necessary to ensure that you receive the healing you deserve.”

Monday’s opening event came in the wake of a series of violent incidents in Dorchester and Roxbury, including the shooting death of a 14-year-old boy in Roxbury last month.

“The recent gun violence in our city has unfortunately increased the community of survivors, but it only deepens our resolve to raise awareness and to invest in trauma care,” Pressley said. “For our babies who will grow up without a parent, for the students who miss their friends, for a sibling that will never see their brother or sister again, you are not alone.”

Pressley cited the prevalence of violence, particularly in communities of color and among young people. According to the Centers for Disease Control and Prevention, homicide is the third-leading cause of death for all people ages 10-24, and the leading cause of death for non-Hispanic Black or African American people in that age range. LGBTQ+ young people are more likely to experience multiple forms of violence than their heterosexual or cisgender peers, and Black or African American young adults are at a higher risk of homicide or assault than other young adult demographics.

Pressley was joined Monday by two elected officials who have lost family members to violence: state Sen.-elect Liz Miranda, who lost her brother in 2017, and state Sen. Nick Collins, who lost a cousin in 2005.

“I have this dual role of serving as a legislator, but also as a survivor,” said Miranda, who was elected earlier this month to represent parts of Jamaica Plain, Mission Hill, Brookline and Roslindale. “It's an important voice, a beauty of resilience, a strength that we must take into all the spaces that we occupy. … It's not easy, but remembering our loved ones and making sure that other families have what they need during their time of need is incredibly important.”

The Louis D. Brown institute will continue events throughout the following 30 days, including group meetings focused on how to cope during the holiday season, special recovery sessions for siblings of homicide victims and the 12th annual breakfast for survivors of victims of homicide with District Attorney Kevin Hayden on Dec. 15.

The work continues to lift up the memory of those who died and push for greater resources for their survivors, Clementina Chéry told the group in her final remarks.

“We are standing firm, and we are more than our tears,” she said. “Massachusetts has been strong because of all of us. We are still going to push things forward. But we've only lasted this long because you guys have seen that this is a worthy cause.”