The former Newcastle United coaching assistant George Ormond was a “wicked” groomer and manipulator who sexually abused young boys dreaming of becoming professional footballers, the jury at his trial has been told.

In a speech closing the prosecution’s case that Ormond sexually abused boys and young men over a 25-year period, the barrister Sharon Beattie asked the jury at Newcastle crown court to consider a person in authority telling children that they were very good footballers, with prospects of becoming professional.

“How wicked, you may think, if all that is a lie to hook people in,” Beattie said. “Just a lie to manipulate those children.”

She referred to the evidence of one alleged victim, who said Ormond had told him, as a boy, that he might play for Newcastle United. Giving evidence, the man had recalled that when he resisted Ormond’s sexual advances, Ormond had told him that he could “crush his dream”.

In this way, Ormond wielded power over the boys who played for the local football club where he was a coach, Beattie told the jury. She described him as an opportunist who ingratiated himself with the boys’ parents.

“George Ormond had a talent for ingratiating himself, with people, parents and children,” she said.

Referring to evidence that Ormond indulged in sexualised conversation and behaviour with young footballers at the local club, and said nothing after the alleged abuse took place, Beattie said this was part of making it seem normal.

“You might think this is the action of a classic groomer and manipulator,” she said. “That’s exactly what grooming is: the manipulation of young people.”

Ormond is charged with one count of buggery, 36 counts of indecent assault and one of indecency, alleged to have been committed against 19 victims between 1973 and 1998.

He is accused of committing the offences while coaching at the local football club, while helping with extracurricular activities at a school and as a coaching assistant in Newcastle United’s youth system from 1993 to 1998. The youngest victim is alleged to have been 11 when Ormond sexually abused him.

Ormond, whom the jury heard had been convicted in 2002 of 13 counts of indecent assault against boys playing for the local club between 1975 and 1999, opted not to give evidence himself in this trial. His barrister, Rebecca Trowler QC, has said that he denies that any of the alleged abuse or incidents took place.

Beattie addressed the suggestion that the witnesses had been colluding, or “jumping on a bandwagon”, pointing to similar evidence being given by people who did not know each other of alleged incidents taking place 20 years apart. Referring to the shame and embarrassment that witnesses said they felt about the alleged abuse, Beattie told the jury: “If it is a bandwagon, it is one they are reluctant to be on, you might think.”

None of the alleged victims can be named for legal reasons. Beattie and Trowler are scheduled to conclude their speeches to the jury on Tuesday.

The judge, Edward Bindloss, is expected to sum up the evidence on Wednesday, before the jury of six women and five men retires to consider the verdict.