Nikki Allan was killed in a derelict Exchange Building near her home in Hendon, Sunderland, by David Boyd in October 1992, jurors at Newcastle Crown Court were told.

Aged 25 at the time, Boyd is accused of hitting Nikki at least once, leaving her bloodied, before forcing her into the derelict building through a boarded-up window.

"Inside the building, the man who took her there beat Nikki Allan about the head with a brick," Richard Wright KC told jurors.

"He shattered her skull. He then used a knife to stab her repeatedly through the chest, the knife being driven in and out of her body many times through the same hole, into her heart, into her lungs, making sure of the job of killing her."

Boyd - now aged 55 - was well-known to Nikki's family and the boyfriend of her babysitter, the court heard.

On the night of her death, Boyd told police he saw Nikki, and by his own account, was "the last man to describe seeing her alive".

The schoolgirl's body was found dumped in the corner of a basement room, where the court heard the killer hoped it would remain undetected.

She was found the next morning by two residents who joined the search to look for her. A child's purple coat and red shoe was found in the area near the building.

George Heron was charged with her murder in 1993 and tried at Leeds Crown Court, where the jury found him not guilty.

"George Heron was not the killer of Nikki Allan," Mr Wright said.

"The killer of Nikki Allan was David Boyd, the man sitting in the dock at the back of this court."

Breakthroughs in technology meant Boyd's DNA was found in "multiple areas" on Nikki's clothing.

The jury was told that Boyd had not been treated as a suspect at any point during the original police investigation but that he was first arrested on suspicion of murder in April 2018.

Boyd was arrested again and interviewed in 2019. When asked to explain why his DNA had been found on Nikki's clothing, he said he had spat over his balcony while Nikki was playing below and it "must have soaked through her clothing and onto her skin".

Mr Wright said a witness also saw a young girl skipping alongside a man, and two screams were heard at around 10pm that night.

"As you know the little girl was plainly happy to be walking with her killer suggesting somebody that was known to her and who she trusted," Mr Wright told the court.

Boyd had also visited the derelict building with a 12-year-old boy days before Nikki died. The court was told he was familiar with the interior.

The prosecution does not have to prove a motive - but the jury was invited to conclude the killer did not lure Nikki away for a "benign reason", Mr Wright said.