Arrest details on mom of Bristol Palin boyfriend

updated 7:24 p.m. ET Dec. 25, 2008

ANCHORAGE, Alaska - The mother of Bristol Palin's boyfriend sent text messages to two police informants discussing drug transactions before her arrest on felony drug charges, authorities say.

An affidavit filed Monday says Sherry L. Johnston sent text messages referring to "coffee" as a code for the drug OxyContin.

The 42-year-old Johnston was arrested last week after state troopers served a search warrant at her Wasilla home. She is out on bail.

Johnston is the mother of 18-year-old Levi Johnston. Gov. Sarah Palin announced in September that her 18-year-old daughter Bristol was pregnant and Johnston was the father.

Authorities say the case began in the second week of September — a couple of weeks into Palin's campaign as Republican vice presidential candidate — when drug investigators intercepted a package containing 179 Oxycontin pills. That led to the arrest of the suspects, who agreed to be informants.

According to the affidavit, Johnson sent a text message to one informant on October 1, writing: "Hey, my phones are tapped and reporters and god knows who else is always following me and the family so no privacy. I will let u no when I can go for cof."

Ten days after Johnston said there wasn't enough privacy for a drug sale, she texted again to set up a meeting at a store, according to the affidavit. The document says the informant received $800 to make a purchase, meeting investigators later with 10 pills of 80-milligram Oxycontin.

A second purchase was made the following day, authorities said. This time the informant wore a hidden camera and a microphone.

A third purchase occurred Nov. 26. The informant was wired for the transaction and this time police videotaped the meeting.

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