Brno, Dec 14 (CTK) – The Municipal Court in Brno extended the pre-trial custody of U.S. citizen Kevin Dahlgren, 23, charged with a four-time murder in the Czech Republic, and rejected the proposal for his release on bail Monday.

If found guilty, Dahlgren would face 15-20 years in prison or even life imprisonment .

The multiple murder was committed in Brno-Ivancice in 2013 and the motive is still unknown. The police keep investigating the case.

Dahlgren has been in pre-trial custody in Brno-Bohunice since August when the United States extradited him to the Czech Republic for prosecution.

This has been the first case of the USA extraditing its citizen to the Czech Republic.

Detectives said repeatedly they had gathered enough pieces of evidence to prove Dahlgren guilty of the murders.

Dahlgren asked for release on bail in August, but the court rejected his request without dealing with the bail level at all.

Dahlgren´s defence lawyer Richard Spisek told CTK before Monday´s proceedings that his client was aware of “the chance of his release being unrealistic.”

He is kept in a custody prison section with tightened security designated for dangerous detainees who could threaten others.

Dahlgren is charged with having killed his cousin, her husband and their two sons in Brno, where he worked as an English teacher, in May 2013. He pleads not guilty.

After the murder, Dahlgren took taxi to reach Vienna, from where he left for the United States. During the flight, the Czech authorities issued a warrant for his arrest, based on which he was detained by the FBI on his arrival at the Washington airport on May 23.

Dahlgren was in custody in the United States from May 2013. The Czech authorities were negotiating about his extradition that was approved in late August.