The father of Diren Dede, a 17-year-old German exchange student shot dead in Montana, criticized the gun culture in the U.S. Thursday.

"America cannot continue to play cowboy," Celal Dede told the German news agency dpa after arriving in the U.S. to arrange the transport of his son Diren's body back to Germany.

Dede said he had never imagined his son could be shot for simply entering somebody's property.

"I didn't think for one night that everyone here can kill somebody just because that person entered his backyard," Dede said.

The 46-year-old father said he wouldn't have allowed his son to participate in the exchange if he had known.

Dede said he hoped the man would receive a fair punishment.

Dede killed inside garage

Markus Kaarma, a homeowner in Missoula, Montana, on Sunday fired four blasts from a shotgun into his garage, killing Diren Dede who was inside. He faces a charge of deliberate homicide.

It's not clear what the teen was doing in the garage. Prosecutors allege Kaarma shot into his garage without warning after Dede tripped sensors.

Kaarma's attorney, Paul Ryan, told The Associated Press Wednesday the homeowner didn't know whether the boy was armed or what his intentions were when he entered the garage.

"The young man made a choice and put the wheels in motion that ultimately created this whole situation," Ryan said.

Kaarma told investigators his Missoula home had been burgled twice within the last week before Sunday's shooting. Kaarma told his hairdresser he had stayed up three nights waiting to shoot a kid, the woman told investigators.

The night of the shooting, Kaarma and his partner, Janelle Pflager, left their garage door open. Pflager left her purse in the garage "so that they would take it," she told a police officer. She also set up a video baby monitor and installed motion sensors, prosecutors said.

After midnight, they heard the sensors trip. Pflager turned to the video monitor and saw a man in the garage. Kaarma took his shotgun and went outside.

Heard sensors trip

He told investigators he heard metal on metal and without speaking fired four times — sweeping the garage with three low shots and a high fourth shot. Dede was hit in the head and the arm.

Montana's law, passed in 2009, says a person is justified in using deadly force if they believe it necessary to prevent an assault or a forcible felony.

Ryan, said that law shifts the burden to prosecutors, who will have to prove that deadly force wasn't justified, he said.

Kaarma didn't intend to kill Dede, Ryan said. "He was scared for his life."

The case has intensified the debate about America's so-called "stand your ground" laws. The principle became central to the defence of a 2012 shooting of an unarmed Florida teenager, Trayvon Martin, by a neighbourhood watch volunteer. George Zimmerman was acquitted last year.

Dede's mother and two sisters, hundreds of friends and neighbours and members of his soccer club arranged a farewell game Wednesday night in his hometown of Hamburg.

Many were sporting T-shirts with Dede's picture on it and held up posters and photos of the killed teenager.

A big banner saying "Our brother is dying while America is looking on" was put up on the sidelines of the soccer field. Some bystanders laid roses for Dede.

Dpa reported that Dede would be buried in Bodrum, Turkey, after a memorial service at Yeni-Beyazit Mosque in Hamburg. Dede's relatives are German-Turkish immigrants.

The teen was studying for a year at a high school in Missoula and was to leave the U.S. after the school term ended in just a few weeks.