(MN) - Sonoma County Sheriff Robert Giordano is firing back against accusations by a top U.S. Immigration and Customs Enforcement official that he refused to cooperate with the agency and hold an undocumented immigrant who now stands accused of setting fire to a Sonoma Valley park in the midst of the deadly Wine Country infernos.

Jesus Fabian Gonzalez was arrested Sunday, a week after numerous firestorms broke out across the region, on felony arson charges. He told deputies he set the fire at Maxwell Farms Park to keep warm, Giordano said in a post on the sheriff’s office’s Facebook page Thursday. The sheriff noted that the cause of the conflagrations that have killed at least 42 people and destroyed thousands of homes is still under investigation.

“We don’t know if these fires were arson or caused by another source,” Giordano said. “There is no indication that Gonzalez had anything to do with these fires and it appears highly unlikely.”