Nearly two years after a teenager and her girlfriend were both shot in the head on a grassy hillside in South Texas, killing one of them and leaving the other with serious injuries, authorities have arrested a man in the attack.

David Malcolm Strickland, 27, was arrested Friday by U.S. Marshals and Texas Rangers in the San Antonio suburb of Helotes, local media reported. U.S. Marshals, Texas Rangers and the police officers from Portland, where the attack occurred, detained Strickland and his wife, Laura Kimberly, 23.

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He is facing charges of capital murder, aggravated assault with a weapon and aggravated sexual assault in the June 23, 2012, attack on Mollie Olgin, 19, who died in the shooting in Portland on the Corpus Christi Bay. Olgin's girlfriend, Kristene Chapa, then 18, survived. His wife faces charges of tampering with evidence.

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“I hope that it gives them some closure knowing that this person is taken off the street,” Portland Police Chief Gary Giles said of the victims’ families and the community. “It is one day before the two-year anniversary. We've been working very hard to make sure we get him as soon as possible. A series of fortunate events has led us to this point and I'm just very happy that we could help in — at least at this point — in bringing him to justice.”

David Malcolm Strickland, 27, is facing charges of capital murder, aggravated assault with a weapon and aggravated sexual assault in the June 23, 2012, attack. Courtesy of Bexar County Sheriff's Office

“He’s a stone cold killer who thought he got away with murder, but will finally pay for his crime,” said Robert R. Almonte, United States Marshal for the Western District of Texas. “My sympathies and condolences go to the victims and their families who had to endure this wicked act of violence.”

Chapa, now 20, had gone with Olgin that Friday night to Violet Andrews Park in Portland outside Corpus Christi to see where her girlfriend had been baptized. The suspected shooter allegedly forced the girls down a steep incline in the quiet bayside park, bound them and shot them in the head. A couple out bird watching the next morning found the girls — Olgin had died but Chapa, who tried to claw her way out of the thorny brush, was alive.

The gunshot initially left Chapa unable to sit or stand, with the bullet piercing the part of her brain controlling movements on her left side. She has recovered those abilities but was still recently undergoing physical rehabilitation.

Messages left by NBC News seeking comment from Chapa and her family weren’t immediately returned. But after a police press conference on Saturday announcing the arrest, she told the Corpus Christi Caller-Times that though she felt safer: “It will never take back the pain and hurt he did to our families. And it won’t bring Mollie back,” she said.

Kristene Chapa, 19, in her bedroom at the Chapa residence on June 11, 2013 in Corpus Christi, Texas. Erin Trieb / for NBC News, file

“Thanks everyone for the texts, messages, and calls but my family and I are just kinda in shock and just shook up,” Chapa wrote on Facebook after the arrest was made. “We need time to let it sink and just process the news we've waited on for 2 years. Please keep us in your prayers.”

Authorities said last year they didn’t believe the attack was a hate crime, but they hadn’t established a motive.

Strickland was expected to be transferred to a jail in Sinton, outside of Portland, on Saturday, Giles said.

“This is still an active investigation. We have a lot of evidence to still continue to process,” he said. "There are still a lot of things that that we cannot release but we're confident that we do have our person."