Copenhagen, Denmark - Peter Madsen, who killed the Swedish journalist Kim Wall in a submarine, briefly escaped a suburban Copenhagen prison Tuesday but was captured by the police a few minutes later. He confessed to threatening several people during his attempted break-out.

According to his defense lawyer Anders Larsen, Madsen responded "yes" when a judge asked him if he confessed to the new charges during a custody hearing at Glostrup City Court on Wednesday.

The authorities convicted Madsen on six new charges, including his attempted escape and threatening a psychologist and a guard on his way out, local news reported.

The police believe that Madsen received outside help, however, it remains unclear if anyone else was involved as Madsen continues to deny he had support.

Madsen tried to break out on Tuesday, but the police recaptured him five minutes later, around half a mile from the jail. Prison employees informed the authorities that Madsen had jumped into a white van. He told the officers who handcuffed him that he was wearing an explosive belt. But prosecutors later found out his threat was fake.

Madsen is serving a life sentence for the murder of Kim Wall, a 30-year-old Swedish reporter whom he had lured aboard his submarine in 2017 with the promise of an interview.