Maria Reyes holds a dress her daughter Damaris was going to wear for a Sweet 15 Quinceanera celebration. (Dan Morse/TWP)

Maria Reyes snapped her eyes shut as monitors in the Fairfax County courtroom lit up. Not only had the MS-13 attackers taken her daughter’s life, they had also filmed her final, agonizing minutes.

Now the clips were the central piece of evidence in a murder trial in the death of 15-year-old Damaris A. Reyes Rivas, a high-profile case that helped propel MS-13 to a top issue in the Virginia governor’s race.

Damaris appeared on the screens with chubby cheeks, stonewashed jeans and a black T-shirt that read “ ’Ello Darling.” She looked young, like a girl ready for the mall.

But she was in snow-dusted woods in Springfield on a brilliant January day, surrounded by taunting associates of MS-13. One ominously clicked a cigar cutter while the girl was told in Spanish that she might lose a finger. They warned Damaris that they had a rifle and gas.

They shouted at her, demanding information about her role in the slaying of their clique leader, Christian Sosa Rivas, who was set up and killed with machetes, tree limbs and rocks in Prince William County about a week earlier. They blamed Damaris for luring him to his death.

15-year-old Damaris A. Reyes Rivas of Gaithersburg, right, is shown with her mother, Maria Reyes, left. (Family photo)

Then the screen faded to black. Tears rolled down the cheeks of Maria Reyes.

She would have to endure more horrific clips before a jury returned a verdict of guilty of second-degree murder Tuesday against Wilmer A. Sanchez Serrano, 22, one of 10 young people charged in connection with Damaris’s torture and killing.

The jury sentenced him to 33 years in prison. A judge will issue a final sentence March 23.

The videos are one of the most chilling testaments to date of the resurgence of MS-13, a gang whose brutality has claimed dozens of lives in the Washington area and up and down the East Coast in recent years.

The cruelty on display on the screens stunned the courtroom into silence and forced a grieving mother to experience her loss all over again.

Maria Reyes had brought Damaris to the United States from El Salvador at age 12 to escape MS-13, which menaces the country. But the girl had left their Gaithersburg home in mid-December and fallen in with members of the same gang.

Prosecutors said that Damaris was lured to Lake Accotink Park in Springfield on Jan. 8. There, she was met by Sanchez Serrano, then 21, and nine members of MS-13. The youngest were 15.

Prosecutors said the group beat and kicked Damaris while interrogating her about Sosa Rivas’s slaying. They moved her around the park on a bitterly cold day over a couple of hours.

Sanchez Serrano testified in his own defense, admitting his role in the killing but saying he was tricked into going to the park and was not a member of MS-13.

He said he was threatened with death if he did not participate in Damaris’s killing.

“If I did that, it’s because they made me,” Sanchez Serrano said through an interpreter during his testimony.

Three other defendants were convicted in October of their role in Damaris’s killing. A handful of others are awaiting trial or plea hearings.

The second video begins a short while after the first. Damaris, wearing neither a shirt nor shoes in the woods, is seen shivering violently.

Prosecutors said the gang forced the girl to strip because they wanted her to feel the same chill Sosa Rivas felt the day he was killed and dumped in an icy Potomac River.

Venus Romero Iraheta, 17, who is charged with murder in the case, is seen wielding a large hunting knife.

“What the f---!” someone shouts off-camera in Spanish. “Just stick the steel in her.”

But the torture would not end so quickly.

Prosecutors said Damaris was taken to a final location nearby, adjacent to a Beltway overpass. Iraheta, who dated Sosa Rivas, then confronted Damaris one last time, an FBI agent testified at an earlier hearing. After Damaris admitted that she had a sexual relationship with Sosa Rivas, Iraheta grew enraged.

Iraheta listed her full name so Damaris would know the name of her killer and then “told the victim she would never forgive her and would see her in hell,” the agent testified.

Iraheta then allegedly plunged the knife into Damaris’s abdomen and neck, again and again.

As prosecutors prepared to play the third clip, which was taken after the stabbing, Maria Reyes cringed as if expecting a blow. The video lasted just seconds, but it showed Damaris on her back among the leaves, with blood on a hand and her forehead.

Sanchez Serrano enters the frame with a large tree branch and plunges it into Damaris’s neck repeatedly. After the clip ended, Maria Reyes’s head fell to one side as she was overcome by grief. She clutched a tissue in one hand and wept.

Despite the obvious weight of her loss, Maria Reyes rose on the final day of the trial and took the witness stand. The mother said Damaris was smiley and intelligent.

She played a video of her daughter blowing out candles on a cake, as if to make that the lasting image of the teen, not the ghoulish recordings of her murder. She explained how she buried Damaris in the quincenara dress she never got to wear.

“My girl has suffered so much. I still suffer so much,” she testified through a Spanish translator.

“Sometimes I see other girls on the street. I see them from behind and it seems like I’m seeing her, but they turn around and it’s not her. I wish I could touch her. I wish I could hug her.”