A former MUSC surgical resident who was arrested on a charge of stalking a woman and ordered to undergo a psychiatric evaluation two years ago has been taken into custody again.

Members of the Charleston County Sheriff’s Office SWAT team, working with the Department of Mental Health’s Mobile Crisis Unit, took Karl Ehrens into custody at his West Ashley house about 3:30 p.m. Wednesday, Maj. John Clark said.

The SWAT team action was prompted by disturbing emails and other communications, including some to court officials, since Ehrens arrived in Charleston before his upcoming trial, according to a source close to the case.

Ehrens provided some clues on his Facebook page. He posted a copy of a letter that said he was scheduled for a trial on the harassment charge the week of July 30. It goes on to say he wanted to submit some evidence and was mailing a box of 12 Care Bears to the Clerk of Court.

The July 18 letter asks that the bears be donated to MUSC Children’s Hospital after the trial. He adds a P.S.: “I request that Grumpy Bear be disregarded.”

Another photo shows two dozen Care Bears perched on a couch. The photo was posted July 20, with the message, “I am home.” His Facebook page said he has been living in Boston.

The stalking case started two years ago, when an 18-year-old woman said Ehrens, who was 29 at the time, was harassing her and exhibiting bizarre behavior after she rejected his romantic advances. She said he kept bothering her after she got a restraining order.

The woman said she found boxes of stuffed animals in her driveway that resembled images in messages Ehrens had sent her. She also said she was worried about a cryptic reference Ehrens made online that Sept. 1 of that year would be a decisive day.

A U.S. marshal and several Charleston County sheriff’s deputies arrested Ehrens July 29, 2010, after a brief chase near his West Ashley home. He was charged with harassment.

Magistrate Alvin Bligen ordered Ehrens to be held without bail until he got a mental-health evaluation. A victim’s advocate asked the judge to make monitoring a condition of his release.

Ehrens told the judge at his bond hearing then that the young woman gave him a hug that meant a lot to him.

The woman told the judge: “We were friends. That’s all we were. I’m sorry he couldn’t accept that.”

Ehrens was in the Medical University of South Carolina’s surgical residency program from July 1, 2008, to Feb. 9, 2009. MUSC didn’t give a reason why he was no longer a resident. Ehrens said at his bond hearing that he was wrongfully terminated and planned to continue the program.

On his Facebook page, he notes that he graduated from MUSC in 2008 but calls himself an author.

Glenn Smith contributed to this report. Reach Dave Munday at 937-5553.

or twitter.com/dmunday.