HOUSTON – Months before Andre Jackson’s arrest for the murder of Josue Flores, the Houston Police Department’s cold case unit began retesting evidence.

Jackson, who had previously been arrested for Flores’ murder before charges were dismissed, had his attorney file a motion with the court for HPD to return his belongings. Those included: two cell phones and charges, a backpack, a USB drive, paperwork and his clothing.

HPD returned all of those items but his clothing, asking the court to allow the department to keep his clothing because it continues “to be needed as evidence in an investigation,” according to court documents, and that “to return those items now would materially interfere with the ongoing investigation into the death of Josue Flores.”

Jackson was arrested Tuesday morning after a grand jury indicted him for Flores’ murder. A key part of that indictment, HPD sources tell KHOU, is a jacket belonging to Jackson.

That jacket, sources say, was sent to a lab in Florida for DNA testing.

Harris County District Attorney Kim Ogg said in a news conference Tuesday that newly tested evidence linked Jackson to the murder. She declined to say what exactly that evidence was, citing all evidence will be presented in court.

Jackson was originally charged with Flores’ murder in June 2016, a month after Flores was stabbed 20 times on his walk home from school. Police said a man was caught on surveillance camera running from the scene matched Jackson's description.

Those charges were ultimately dropped in July 2017 because DNA evidence at the time was inconclusive.

Houston Police Chief Art Acevedo said in May that evidence in the case was being sent to a Florida lab that had capabilities to extract DNA from evidence that local and state labs don’t.

If convicted of murder, Jackson faces five to 99 years in prison.

MORE ON THIS STORY

Andre Jackson charged in Josue Flores' killing

Who is Andre Jackson, the man police say killed Josue Flores?

Andre Jackson in July 2017: 'I did not kill Josue'

Timeline: The heartbreaking case of Josue Flores

HPD chief to child killer: 'We’re going to get you. So come forward now and ask for mercy.'

Controversial Salvation Army shelter closing in north Houston