Image copyright CBS Image caption From left: Savvas and Amy Savopoulos, Philip Savopoulos and Veralicia Figueroa

A man has been convicted for the 2015 murders of four people inside a Washington DC mansion that shocked residents of the nation's capital.

Daron Wint, 37, was found guilty of all 20 charges against him, including first-degree murder, kidnapping, burglary, extortion, arson and theft.

Prosecutors say Wint's DNA was found on a slice of pizza that was delivered to the home on the night of the abduction.

Firefighters discovered the dead family the next day as their house burned.

Police believe the victims - Savvas and Amy Savopoulos, their 10-year-old son Philip and housekeeper Veralicia Figueroa - were tortured inside the family's $4.5m (£2.9m) home in Washington's upscale Woodley Park neighbourhood.

All of the victims were found beaten, strangled and stabbed inside the burning mansion on 14 May 2015.

Image copyright Getty Images Image caption Firefighters who were called to the blaze were the first to discover the slain family and their housekeeper

During the trial, a medical examiner testified that the 10-year-old boy was possibly burned alive, though the injuries were too severe to be conclusive.

During the six-week trial, more than 60 witnesses were called to testify, including experts who said that Wint's DNA was found on pizza as well as other items inside the home, including a knife.

Motivated by 'greed'

Prosecutors say that Wint, who had previously been employed as a welder at a company owned by Savopolous - had fallen on hard times, which motivated him to kidnap the family and demand a $40,000 ransom.

"He had no options left. He did this. He's the one who killed these people," said Assistant US Attorney Laura Bach during the trial's closing arguments.

Image copyright Reuters Image caption Daron Dylon Wint, as seen in a 2007 police photo

"Now you hold him responsible. Hold him accountable for what he did," she said, according to the Washington Post.

The victims were killed despite paying Wint the ransom money through an assistant of the Savopolous family.

During the trial, Wint surprised the court by taking the stand to testify in his own defence, and claimed that the murder had actually been orchestrated by his half-brother.

Media playback is unsupported on your device Media caption Mr Wint was arrested in Washington one week after the murders

Prosecutors acknowledge that he may have been helped, but Mrs Bach said: "Even if Daron Wint had help, he's still guilty."

According to expert testimony, Wint, who was arrested nearly a week after the attack, used his mobile phone to search online: "How to beat a lie detector test" and "10 hideout cities for fugitives".

During the trial, the family's grandfather testified of the boy's love of Harry Potter and trains.

The couple's two daughters were away at boarding school at the time of the attack.

He is due to be sentenced on 1 February.