Traces of April Jones's blood and burnt bone fragments believed to be from a child's skull were found at the home of the man accused of abducting and murdering the five-year-old girl, a jury has been told.

The court heard that a number of knives including a burned boning knife were also discovered near a wood-burning stove at the cottage of Mark Bridger, an experienced slaughterman who falsely boasted of having been in the SAS.

Opening the case against Bridger, Elwen Evans QC alleged that April was the victim of a "sexually motivated" crime when she was seized from an estate in Machynlleth in mid-Wales while out playing on her bicycle. The jury viewed a slideshow of images taken from Bridger's computer that included explicit child pornography as well as victims of notorious murders including Holly Wells and Jessica Chapman, who were killed by school caretaker Ian Huntley in Soham, Cambridgeshire.

In addition, Bridger had collected images of April's 16-year-old and 13-year-old half-sisters, some of which included the five-year-old herself, it was claimed.

On the day April was allegedly abducted, Bridger split up with a girlfriend, asked a number of women out for a drink and looked at a cartoon image of a girl being raped while she was restrained.

He is claiming he had accidentally hit April in his Land Rover, bundled her into his car and has forgotten what had happened afterwards and how he had disposed of the body. But Evans said Bridger was playing a "cruel game" and knew "full well" what happened to April but was choosing not to say.

Bridger, 47, denies abduction, murder and intending to pervert the course of justice by disposing of, concealing or destroying April's body, which has never been found.

Evans told the jury of nine women and three men that on the evening of 1 October last year, April was playing with a friend near garages not far from her home on the Bryn-y-Gog estate in Machynlleth.

The court was told that April went to the local school and was doing well. She had a mild form of cerebral palsy but that did not stop her leading an active life and on the day she disappeared she had been swimming before going off to play on her beloved bicycle.

Evans told the jurors that April's friend would give the court her account of what happened next. The friend told police that she saw April going over to a man who was sitting in his car. The man talked to April and the little girl got into the car. The friend did not know what either had said but the friend said April was "happy and smiling".

"That was the last that anyone apart from the defendant saw April," Evans told the court. The alarm was raised by another child who had been sent to fetch April home. The child ran back, hysterical, crying: "April has been kidnapped."

At 7.29pm, April's mother made a 999 call to the police saying that her daughter had disappeared. The harrowing call was played in court, prompting Bridger to appear to wipe a tear away.

Evans said Bridger told a very different story. His case is that he accepts he killed April or probably killed her and that he must have got rid of her body.

He told police that as he drove off in his Land Rover he hit April and "crushed" her. He pulled her out unconscious from beneath a front wheel and laid her on the front passenger seat before driving off intending to get medical attention.

The prosecutor said Bridger could have sought help on the estate, driven to a nearby hospital or called for help on his mobile phone. Instead he drove from Bryn-y-Gog using the "back road".

Bridger says he could not remember how he disposed of the body, though he did at one point tell police he had put her out of the rain. He claimed a combination of drink, panic and adrenaline had led to his memory loss.

But the prosecution alleges that Bridger actually went to enormous lengths to try to cover up what he had done. Evans claimed that had April's body been found his motive – a sexual one – would have been exposed.

"He has played a cruel game," she said. "It's a game to try to save himself and manipulate himself out of his responsibilities," said Evans. Bridger told police he had not taken April to his home, a whitewashed cottage called Mount Pleasant in the village of Ceinws, three miles from Machynlleth. But police found what the prosecution claimed was an "extensive clean-up operation" there, allegedly to dispose of April's clothes and body.

Despite the clean-up, police found traces of April's blood in the living room, hall and bathroom of his home, it was claimed. There was a "concentration" of her blood in front of a woodburner in the living room under a carpet and on the hearth. There were a number of knives around the burner including a burnt boning knife, Evans said.

The prosecutor added that Bridger was an experienced slaughterman who knew how to use knives. He had worked at an abattoir between 2009 and 2012.

Small burned fragments of bones were found. Because they had been subject to high temperatures it had not been possible to identify the fragments but experts believed they were from a human juvenile.

Evans said it was not up to the prosecution to prove a motive but she said an examination of Bridger's laptop gave an insight into his "interests and mindset" and gave context to his behaviour to April.

He had a "clear interest in child pornography, photos of local girls and child murder cases", Evans said.

The public gallery was cleared so that a slideshow presentation of what Bridger had been viewing on his laptop could be screened. April's parents stayed to watch, flanked by police family-liaison officers.

A series of images of April's half-sisters, aged 13 and 16, that had been stored in folders on his computer were shown. Some had been taken from Facebook.

Asked why he had pictures of the 16-year-old girl, Bridger told police he thought she was "beautiful … an up-and-coming local model", Evans said.

Some of the images also featured April. The prosecution said he viewed pictures featuring April eight days before she went missing.

In another folder, Bridger had allegedly collected images of Caroline Dickinson, a British teenager who was killed in France, and an American child-murder victim, Jessica Lunsford. He had also stored images of the 10-year-olds Holly Wells and Jessica Chapman.

Search terms he had allegedly typed into his computer included "naked five-year-old girls", "ten-year-old girl naked" and "pictures of naked virgin teens".

The jury was shown a picture of a pregnant eight-year-old girl, which he told police he found "astonishing and interesting". Also on the slideshow was the deathbed picture of a child in Thailand and another of a young girl apparently hanged.

Some members of the jury looked shocked as they were shown pictures of child sex abuse in a file labelled Z-zero. A few were cartoons but many others featured girls being sexually abused.

When interviewed by the police, Bridger claimed he had looked at some of the images to understand the development of his own daughter and to help her become a model.

He had also stored some of the explicit images because he planned to make a complaint about them.

The jury heard that Bridger told police he spent a lot of time outdoors practising "survival and bushcraft" and had "excelled" during a career in the armed services, including the SAS. But Evans said military records had been checked and no record of him had been found. She said it was a "lie, a fantasy".

The trial continues.