It was an unprovoked act of violence on the streets of Dorchester that pushed a young Marilyn Mosby to a career in law enforcement. Now, it is another deadly encounter that has propelled her to national prominence.
Twenty-one years before Mosby, the top prosecutor in Baltimore, captured the country’s attention by charging six police officers in the death of Freddie Gray, she was a 14-year-old mourning the death of her cousin outside the door of her family’s home in Dorchester in 1994.
Diron Spence, who was 17, was shot and killed on his bicycle by another 17-year-old who had demanded money from him, according to prosecutors. Family members said they believed Spence was mistaken for a drug dealer.
“He was like a brother to me,” Mosby said in an interview Friday, hours after her nationally televised press conference in which she announced the charges against the officers. She recalled watching her cousin’s killer sentenced to life in prison in Suffolk Superior Court in 1996.
“I wanted to know how could we have gotten to that 17-year-old and stop him before he picked up that gun,” she said. “That’s what inspired me to become a prosecutor.”
The random injustice of the crime, she said, galvanized her to follow five generations of her family into law enforcement, a lineage she hopes will give her credibility as she prosecutes the Gray case, which has exposed a gulf of mistrust between police and the community.
In comments directed at the Baltimore Police Department on Friday, she noted her mother, father, and aunts and uncles were Boston police officers, and her grandfather, Prescott Thompson, was a founder of the Massachusetts Association of Minority Law Enforcement Officers, in 1968.
Like Mosby, her grandfather entered law enforcement after experiencing an injustice.
He told the Globe in 1994 that when he was 12 or 13, four white officers in Roxbury slammed him against a wall and accused him of stealing a purse. He said he decided then that he never wanted that to happen to another black child, and went on to become a member of the so-called Soul Patrol, a unit of African-American officers that worked the streets of Roxbury in the 1970s.
“Is it something that is a part of who I am? Absolutely,” Mosby said in the interview Friday. “That law-enforcement has been instilled in me. I witnessed firsthand the commitment it takes to sacrifice in life for the betterment of your community.”
Mosby, 35, was known as Marilyn James before she married a Baltimore city councilor, Nick Mosby, in 2005.
She was raised in Dorchester by her grandparents, she said. Her mother, Linda Thompson, was 17 when Mosby was born and the two “grew up like sisters,” Mosby said.
On Friday, Thompson, now a retired Boston police officer, was celebrating her daughter’s decision to bring charges in Gray’s death and to hold a passionate press conference to address public anger over police brutality.
“I can’t stop crying with pride!” she wrote on Facebook. “She is a hero not only to me but, right now, to the world.”
A cousin, Boston police Officer Poncho Kincade, said he was shaving Friday morning when he heard Mosby’s name on the news. “I was like, ‘Oh my goodness,’ ” he said. “Everyone that knows her is so proud.”
A product of the METCO program, which buses minority students from Boston to suburban schools, Mosby graduated from Dover-Sherborn High School in 1998. She was one of only three black girls in the school and a co-editor of the student newspaper, she told Afro.com in 2013.
In 2002, she graduated from Tuskegee University, a historically black college in Alabama, and returned home to attend Boston College Law School, where she was drawn to both sides of the law, defense and prosecution.
In 2004, she was an intern in the homicide unit of Suffolk District Attorney Daniel F. Conley’s office, where prosecutors remember her as “very smart, focused, and hard-working,” Conley said.
She also trained as a criminal defender, said Sharon Beckman, supervisor of the BC Defenders Clinic.
“Marilyn pushed herself to look at the criminal justice system from different points of view,” Beckman said. “She comes from a law enforcement family but, in our BC Defender Clinic, she represented individuals charged with crimes zealously and with great compassion. She understood deeply the corrosive effect of unequal application of the law.”
After graduating from BC Law in 2005, Mosby moved with her husband to Baltimore and worked as an assistant state’s attorney and as a lawyer for Liberty Mutual.
She broke into the city’s hard-nosed political scene last year, with an upset victory over the incumbent state’s attorney, Gregg Bernstein, a fellow Democrat.
She had promised to crack down on violent offenders but also to repair the “culture of mistrust” between young people and the police. As she told the student newspaper at Morgan State University in Baltimore in October, “My job, as a prosecutor is to apply justice fairly and equally, with or without a badge.”
On Friday, with the highly charged prosecution in the Gray case looming ahead of her, she reiterated that pledge. There are plenty of good officers like those in her family, she said, but there are also some “who usurp their authority and abuse the public’s trust.”