EASTON, Pa. (AP) — Officials say a former Lehigh University student charged with poisoning his roommate posted $200,000 bail and hoped to be deported to China to avoid prosecution.

They say 23-year-old Yukai Yang is back in local custody after authorities had him returned from federal immigration custody to the Northampton County Jail in northeastern Pennsylvania.

District Attorney John Morganelli said Thursday officials are investigating whether a second student was also poisoned.

Yang is accused of putting the colorless, odorless chemical thallium in his roommate's food and drink over several months.

Yang's lawyer did not immediately return a call for comment.

He'd been charged in the spring with writing racist graffitti on the wall. Yang is charged with attempted murder, aggravated assault, ethnic intimidation and other charges.

A hearing is scheduled for next week.