Hartford police arrested an "extremely dangerous" man accused of killing a 23-year-old Hartford mother found dead in Bloomfield this week, police and sources said.

Robert Lee Graham, 59, of East Harold Street in Hartford, was wanted for the murder of Tashauna Jackson. Bloomfield Police signed an arrest warrant for Graham on Friday evening. Hartford police assisted and later that night, police found him hiding in the attic of his Hartford home at about 11:30 p.m. Friday. Officers took Graham into custody and police arrested him on a murder charge in connection to investigation into Jackson's death.

Authorities in the capital city said Graham has killed before.

Jackson, the mother of a 5-year-old, vanished Aug. 11 after getting into Graham's car near Keney Park in Hartford. Her body was found Tuesday, a week after her disappearance, 30 feet into the woods off Granby Street in Bloomfield.

"Why did you have to kill her? That's what I want to know," wondered Jackson's cousin, Azenia Williams. "You took her from us. We'll never have her back, and it hurts. It's very painful... what you have done to our family."

Jackson's aunt, Vanessa Kingston, said she and other family members showed up at Graham's East Harold Street address hoping for an arrest Friday night – but he was gone.

"I was angry that they didn't get him tonight, very angry," Kingston said before the news he was in custody. "I was really upset when I left there, but they're going to get him."

Now Jackson's family is relieved the man suspected of murdering her is in police custody.

"We've been having restless nights because we love her so much," Williams said. "So, because we loved her we couldn't rest knowing that she was out there, or we couldn't rest knowing her killer was out there."

Kingston said she's "overjoyed."

"Overjoyed. Oh my God, thank you Jesus. I am so overjoyed I don't know what to do," Kingston said. "This monster is off of the streets and he won't be able to hurt nobody else's child."

Bloomfield police said Graham is "extremely dangerous" and has a history of violence. He may have ties to Springfield, Massachsuetts.

"Graham is a violent individual who has killed before," Hartford police said in a statement Friday night. "We are dedicating extensive resources to assist the Bloomfield Police Department in locating this suspect."

Family members told NBC Connecticut police also found DNA evidence of Graham's skin underneath Jackson's fingernails.

Jackson will be laid to rest at 10 a.m. Thursday, Aug. 27 at Mount Moriah Baptist Church in Hartford. A GoFundMe page has been set up to raise money for her funeral expenses.

The state's attorney's office and Connecticut Office of the Chief Medical Examiner worked with Bloomfield and Hartford police on the investigation.

The investigation into Jackson's death is ongoing. Police ask anyone with information on Jackson's disappearance and death to call the Bloomfield Police Department at 860-242-5501.