Richard Frederick Arthur Pruszinski had a hectic weekend, the 17-year-old stole a motorcycle from Broken Hill on the night of Friday the 25th of December 1948, and rode it to Adelaide. He then abandoned the motorcycle in sand hills at Glenelg. Dumped a suitcase containing clothing and a rifle with the barrel missing on Somerton beach, and illegally used a motor car at Port Noarlunga where he was arrested by police.
Fred admitted to the police he had dumped the clothes which were found on Somerton beach. Police found only the clothes and a rifle with the barrel missing, but the youth said he had left them in a suitcase. He said he then walked to Port Noarlunga, where he was later arrested for allegedly having illegally used a motor car. He appeared in the Juvenile Court.
This seems all seems quite strange to me. Why would a 17 year-old steal a motorcycle, drive it all the way from Broken Hill to Adelaide (a distance of about 500km), dump a suitcase full of clothes onto Somerton Beach, walk to Port Naorlunga, and then steal a motor car?!
There is more information about the sadly rather short life of Richard Frederick Arthur Pruszinski at the Ciphermysteries site.