Michael Cavallari's stepbrother Drew Spies told Radar Online in an interview that he was mad at him for making "stupid" decisions, which led to his death. Cavallari, who is the brother of former "Hills" star Kristin Cavallari, was found dead Thursday in Utah after being reported missing for nearly two weeks.

"I’m mad at him," Cavallari’s stepbrother Drew Spies told Radar Online, adding: "He’s a selfish guy." Spies also called Cavallari, 30, "stupid" and reportedly added that the news "is going to wreck his mother."

Grand County Sheriff’s officers found Cavallari's body and reports said that he was on his way to Illinois when he went missing. Officers found his car about five miles south of the Interstate 70, off Exit 175 near Green River, Utah on Nov. 30. The reports added that the car was running and one of the airbags had been deployed. The cause of Cavallari’s death is currently unknown.

According to a report by Daily Mail, which cited a source close to the family, Cavallari was struggling with alcohol issues, which made him "difficult" and "crazy." Cavallari reportedly lived at his father Dennis’ home in San Clemente, California and spent his time drinking, smoking and playing online games, the report said. He refused to find a job and was dependant on his father for financial support.

"Michael is a very difficult person to get along with, he's not all there, crazy," the source said, adding: "He had a room in his dad's house but he was always a huge disturbance to his father's tenants."

"He would play loud music, club bass, until three in the morning, it made one of the tenants very angry, they almost came to blows," the source continued, according to Daily Mail, adding: "The police were also called out when he had an argument with his girlfriend in the street, there was always some drama."

"The tenants complained to him and to his dad but it didn't stop. Michael and his father also had their own issues and Dennis had no choice but to kick his son out because he was upsetting the paying tenants,” the source added.

Four days before he disappeared, Cavallari was arrested for threatening a woman with a shotgun.

Kristin issued a statement Thursday saying, "We want to thank everyone for their love, support and prayers during this very difficult time," adding: "We have just been informed by the authorities my brother's body has been found. This is a very painful time, and we are still processing it all. We kindly ask everyone please respect our privacy during our time of grieving."