Shemel Mercurius was a teenager just trying to make it to adulthood in her rough-and-tumble Brooklyn neighborhood. She lived in an apartment complex with her relatives and was well thought-of to those who knew her.

New York police said that a grown man with a grudge opened fire on her in her Flatbush apartment. The suspect, identified by authorities as Taariq Stephens, 24, of Brooklyn, appeared in court on Monday, December 11, 2017, in the May 2016 shooting.

That's when NYPD officers testified that when they arrived upon the murder scene, they found Shemel's cousin sobbing and doused in blood, according to WPIX.

The relative told police that the victim indicated that the suspect showed interest in her, but was spurned. 

Shemel’s body was found with several gunshot wounds, including one to the chest and multiple holes in her arms. Struggling to breathe, she was able to mouth a description of her attacker to first responders, according to media reports.

Shemel was pronounced dead later at Kings County Hospital Center.

Stephens surrendered to police after police identified him and released surveillance video allegedly showing him entering the complex, according to WCBS in New York. Stephens, who i is charged with murder, is facing 25 years to life in prison.

What made the killing even more grotesque is that Shemel, who had moved to the U.S. from her native Guyana, was actually at her home babysitting her 3-year-old cousin when she was executed.

Days after the brazen murder, friends, family and members of the community held a vigil outside the East Flatbush apartment building on Brooklyn Avenue, where Shemel was struck down.

“Shemel, may your soul rest in peace and you will always be in my heart no matter where you go, what you do, you will always be in my heart,” the teen’s father, Dexter Mercurius, told CBS2.

When the suspect was hauled into court, Shemel’s relatives were able to get a good look at him.

“I wanted to see if I knew this guy but honestly I never knew this guy, I never see this guy,” Dexter Mercurius, the victim’s father, told WCBS. “So I wanted to know why this guy killed my daughter because my daughter is 16 and this guy is 24.”

Authorities are trying to find out why the suspect allegedly used a sub-machine gun to mow down the girl.