Despite much speculation and conspiracy theories, the reason for the mysterious closure of New Mexico’s Sunspot Solar Observatory by the FBI earlier this month was an ongoing child pornography investigation, court documents show.

The secret behind the 11-day closure of the facility was finally explained in newly unsealed FBI records and its application for a search warrant. According to the court documents, the federal agents were investigating a janitor suspected of using the observatory’s WiFi network to download child pornography.