TAMPA, Fla. — An arrest has been made in the murder of 14-year-old Nilexia Alexander, a runaway from Temple Terrace found dead near Floribraska Avenue on May 6.

According to Tampa police, 44-year-old Ronny Walker was arrested by the U.S. Marshal’s Service Thursday afternoon after the Florida Department of Law Enforcement crime lab matched DNA samples from Walker’s car to the victim.

Since Alexander’s body was discovered, detectives have been working to identify a vehicle seen near the scene at the time of the murder.

Once the car was identified as Walker's, police said they worked to use location pings from Alexander’s cell phone to determine she was in Walker’s car around the time of the murder.

Walker now faces one count of premeditated murder with a firearm.

"It won't bring my baby girl back, but it will give me some peace that he's off the streets and a little bit of closure," Ashley Alexander, Nilexia's mother, said during a Friday news conference about Walker's arrest.

This isn't the first time Walker has been accused of murder. Our partners at the Tampa Bay Times report he was found guilty of killing Elaine Caldwell, 45, during a home invasion robbery in 2003.

Caldwell's daughter, Veronica Denson, said she feels the system failed her family.

"He killed a baby. If he would have been in prison, none of this would have happened," said Denson.

Denson said she was laying in bed Thursday when the calls started coming in from loved ones telling her Walker had been arrested in Nilexia's death.

"I just jumped straight up out the bed," she said. "I was like, 'No, he didn't.' Only thing I could say, 'They got him this time. They got him this time. They ain't gonna let him go this time.'

"When that dude killed my mama, he took something from us. He took our whole hearts out."

The Times reports Walker was initially charged with murder in Caldwell's death but was found guilty of the lesser charge of manslaughter and sentenced to life, due to his lengthy criminal history.

Records from the Florida Department of Corrections show Walker was incarcerated on and off since the mid-1990s.

An appeal overturned the sentencing in Caldwell's murder, and Walker ended up receiving an 8-year sentence. Corrections records show he was released in 2016.

Hillsborough County State Attorney Andrew Warren said Walker violated probation in 2017 and served another four years. Records show that after he completed his sentence, he was released in November.      

"I just feel like the system really, really failed me and my sisters and brother because (if) they would have never let him out, he would have never been able to kill this baby," Denson said.

Warren said the reality is that most people in the criminal justice system don't go to prison for life.

"I have confidence that the State Attorney's Office did everything they could to convict him of the charge against him," Warren said.

Denson said that despite everything else, she was just glad that Walker was in custody. 

"Keep him off the street so he won't be able to kill nobody else and have nobody else's family hurting," she said. "Because my family is hurting."