Penn State police have closed the investigation into several harassing phone calls made to athletic department employees days after the charges against former assistant coach Jerry Sandusky exploded.

Police had gotten a search warrant in May.

“Unfortunately, the search warrant execution did not provide any additional information so the investigations were closed since there are no leads or suspects,” university Police Chief Tyrone Parham said Thursday.

One of the calls was made to the Bryce Jordan Center Nov. 18. The caller told the employee he was “looking for some little boys” to have sex with, a reference to the allegations against now-convicted pedophile Jerry Sandusky. According to police, he told the employee: “You’re the ones that let it happen.”

In all, police were looking into four calls as part of their investigation.