Man smirks and tells police 'I'm having a panic attack' after realizing he's been caught years after murdering woman

This is the chilling moment a murderer who had remained undetected two years after his horrific crime was brought in for questioning by police - and started to crack under the pressure.

Chelsea Bruck, 22, disappeared from a Halloween party in Frenchtown Township, Monroe County, Michigan on October 26, 2014.

Her family waited in agony as police drew blanks as to what could have happened to her, with cops conducting an extensive six-month search.

On April 24, 2015, construction workers found a body in a wooded area near the village of Carleton, which was later identified as Bruck. Yet it would be another year until her killer was brought in for questioning.

In July 2016, Daniel Clay was charged in a separate sexual assault case, and his DNA was found to be a match for a sample found on the leggings of the handmade Poison Ivy Halloween costume Bruck was wearing.

Clay was arrested on July 22, 2016, and brought in for questioning.

Monroe County Sheriff's Department

After initially denying ever having met Bruck, Clay began to fall apart under pressure and eventually claimed he had accidentally choked Bruck to death during sex.

He said he panicked and hid Bruck’s body after he realized she was no longer breathing, claiming he tried to resuscitate her.

But the story didn’t add up, as Bruck died from blunt force trauma to the head, and not by asphyxiation.

After two years of thinking he’d got away with the crime, Clay began to crack, telling police: “Can I get a cigarette please? This is about to make me have a panic attack.

“I’m literally feeling myself sweating and about to just start crying and passing out.”

Later in the interview, cops told Clay: “You’re smirking right now.”

Monroe County Sheriff's Department

He responded: “I did stupid s**t. I’m not smirking right now.”

The day of his arrest, Clay told his girlfriend in a voicemail he was 'extremely sorry', had 'f**ked up big time' and was going to be 'gone for a really long time

Clay found himself in court the following year, with the prosecution arguing that he hid Bruck’s body rather than going for help because it would be clear her death wasn’t an accident.

Prosecutor Michael Roehrig argued: “I go back to his response when asked about taking Chelsea anywhere for help. He didn't because they would've seen her injuries, the damage to her costume, the blood and his response, if they had looked.”

The jury agreed, finding Clay guilty of first-degree murder. He was sentenced to life in prison without parole.