Richard Dabate photographed with his wife Connie. Picture: Facebook

Richard Dabate, 40, told police his wife was shot dead by an unknown man who broke into the couple’s home in Ellington, Connecticut, and tied him up in December 2015.

But the gun used in the killing — a .357 Magnum — had been purchased months before by her husband, the Hartford Courant reports.

Richard Dabate shown in court in Connecticut. Picture: Fox61Source:Supplied

Dabate also told police he struggled with the masked intruder, who he said sounded like Vin Diesel, until the man subdued him by applying pressure to his wrists. He claimed the killer then chased his wife into the basement and shot her.

He told detectives he was tied to the chair after the man had murdered his wife and scared the intruder off by kicking a blowtorch at his head.

The family home where Mrs Dabate’s body was found. Picture: Fox61Source:Supplied

However, the records from his wife’s FitBit showed she had been moving more than an hour after her husband said she was dead. CCTV footage from the gym where Mrs Dabate had been working out the night of her death also contradicted her husband’s story.

“To say it is rare to use FitBit records would be safe,” said district attorney Craig Stedman. “It is an electronic footprint that tracks your movements. It is a great tool for investigators to use.”

Date from Mrs Dabate’s FitBit device reportedly contradicted what her husband told police. Picture: SuppliedSource:Supplied

The police investigation revealed that Dabate, who had two sons — ages 9 and 6 — with his wife, had been having an affair with a childhood friend who had become pregnant and wanted him to leave his wife.

According to the Courant, he had even told his lover that he and his wife had talked about divorce and “are on the same page” even though his wife had sent him a flirtatious text the previous day, suggesting she did not know about the affair.

Police also found a file on his wife’s phone dated December 2014 titled, “Why I want a divorce.”