A man who sent threatening tweets to the son of Wisconsin Gov. Scott Walker last summer has pleaded guilty to his actions.

Robert Peffer pleaded guilty to four misdemeanor counts of using a computer to send threatening or obscene messages. He sent 36 tweets over a span of 6 days to Matthew Walker, saying his father had raped him and threatening him, Fox 11 reports.

Walker, is a college student, fear for his dafety and reported the tweets to the law enforcement officer responsible for his protection.

Judge Dennis Flynn sentenced Peffer to 90 days in jail and ordered him to pay a $1,000 fine on the first count. He stayed 90-day jail stints on the other three counts in lieu of probation.

Right Wisconsin notes when Peffer was asked by investigators what he had against Walker’s son, he said, “Nothing at all. It was just because he was Scott Walker’s son. And I have been part of the recall since February 2011.”

Peffer said he disliked Gov. Walker’s politics and Matthew Waker “was just an innocent bystander that is part of Scott Walker.”

According to Right Wisconsin:

According to the criminal complaint, this was not the first time that Peffer has been investigated by law enforcement for lewd and threatening messages online. In 2012, the South Milwaukee Police Department investigated Peffer after Facebook comments he made following the 2012 Colorado movie theater massacre.