YONKERS, N.Y. (CBSNewYork) – A 15-year-old accused of fatally shooting an innocent bystander last month in Yonkers is now in police custody and charged as a juvenile with murder.

Jamir Thompson allegedly opened fire on April 25, killing 18-year-old Marilyn Cotto Montanez. He turned himself in to police with his mother and attorney around 1 a.m. Tuesday.

The young suspect left the YPD youth division sight hours after his early morning surrender. He is being held without bail.

Yonkers Police worked with the FBI, and sent investigators to Connecticut, Florida, Pennsylvania and North Carolina as part of their effort to track them down. Police believe he spent several days in North Carolina traveling with fellow gang members.

“He needed to surface at some point, and if he didn’t, he would’ve been found,” said Yonkers Mayor Mike Spano.

“Today’s surrender of Jamir Thompson is the direct result of the hard work and dedication of the Yonkers Police Department,” said Spano. “Their tireless efforts in tracking this individual gave him no other choice than to turn himself in for his heinous crime against a young woman with a bright future. Great job by our Yonkers’ finest. I look forward to seeing justice served for the sake of the family and friends of Marilyn and our Yonkers community.”

“Jamir Thompson has been taken into custody and will now have to answer for his despicable actions. I applaud the dedication of our Police Officers and Detectives and their on-going, relentless pursuit of justice for the family of Marilyn Cotto Montanez,” said Yonkers Police Commissioner Charles Gardner.

Thompson faces second degree murder charges.

Thompson evaded police for eight days after he was named as the gunman who allegedly shot and killed Montanez.

Montanez was walking with her 9-year-old sister to get pizza and was not the intended target. Thompson allegedly fired at a rival.

Text from Juan Cotto, brother of Marilyn Cotto Montanez: "this is good she will have peace my family can now sleep." Family lives 1/2 block from spot where Marilyn was struck by stray bullet while walking 9yo sister to the store. https://t.co/U56G1zoohT — Tony Aiello (@AielloTV) May 7, 2019

“He’s a young man with no convictions, from a nice, humble family,” said Thompson’s attorney Lisa Pelosi. “Our hearts go out to the victims’ family. This is a tragedy for everyone. He’s here to say he’s not guilty and he’s going to fight the case.”

“He’s lived his whole life n Yonkers. They’ve been wanting to surrender him but the circus surrounding this tragedy put them in a position where they wanted to do it properly,” said Pelosi.

Thompson’s mother and grandmother were in court as he was being arraigned.

Prosecutors said Thompson’s mother was “obstructionist,” Aiello reported. Prosecutors said she told police she knew where he was while police were looking for him, had spent time with them but would not help them locate him.

“We are continuing the investigation including the actions of the mother, and if we are able to develop a case or information that supports her harboring him, we will work with the district attorney and place her under arrest,” said Yonkers Police Commissioner Charles Gardner.

When he heard Thompson had surrendered, Montanez’s brother told CBS2’s Tony Aiello “This is good. She will have peace. My family can now sleep.”

At just 15, Thompson already has a criminal history.

BREAKING: We got him! 15 yr old Jasmir Thompson, wanted for shooting and killing innocent teen Marilyn Cotto Montanez, is in custody of the @YonkersPD. More info to come from YPD later this AM #yonkers — Mayor Mike Spano (@MayorMikeSpano) May 7, 2019

In 2015, he was charged with knife-point robbery. In 2017, he was arrested again for possession of a loaded .380 caliber gun, and last November, he was charged with stabbing someone in the leg during a dispute.

Court records show that his father died when Thompson was a young man.

Thompson’s social media accounts are filled with pictures of him showing off money, marijuana and flashing gang signs.

As a juvenile offender, if convicted of second degree murder, he’ll face a maximum of seven and a half years to life in prison.

Thompson’s attorney indicated she wants him to testify to the grand jury responsible for an indictment.

A GoFundMe account has been started to raise money for Montanez’s 9-year-old sister to get therapy after witnessing the shooting.