The teenager arrested in the slaying of a prominent defense attorney's wife once drew a pentagram on the ground at school and told other students he was reading from the book of Satan, according to former classmates.

Authorities would not identify the 16-year-old, but the boy's name was widely publicized after his arrest late Wednesday. Police were still working to determine a motive for the beating death of Pamela Vitale (search), the wife of lawyer and TV legal pundit Daniel Horowitz (search).

"Although we have a suspect, the investigation is still going on," Contra Costra County Sheriff's Department spokesman Jimmy Lee said.

Vitale, 52, was slain over the weekend at the hilltop estate where the couple were building their dream home in the wealthy San Francisco suburb of Lafayette. The teenager lived down the hill on a remote canyon road.

Ivan Golde (search), a friend of Horowitz and his co-counsel, said Horowitz didn't know the teen well.

"Dan knew the family somewhat but he didn't really know this kid. He had no connection to this kid," Golde told NBC's "Today" show Friday.

The suspect was described as a quiet student at Acalanes High School (search) in Lafayette, where he stood out because of his attire.

"He was really gothic, always wore a long, dark jacket," said Kevin Etheridge, 16. "He'd hang out with a few kids, but he was pretty quiet, pretty much to himself."

Another student remembered him drawing a pentagram on the ground with chalk in junior high school and dancing around it with other students.

"He told people the book that he was carrying and reading from was the book of Satan," Keith Kingon said.

A man at the house where the suspect lived declined to comment Thursday as goats and chickens wandered around the property. A potbelly stove, a bathtub and dozens of baseballs littered the yard.

The San Francisco Chronicle, citing an unidentified law enforcement source, reported that investigators believe the killing was related to a scheme that involved using stolen credit card numbers to fund a marijuana-growing operation.

The source said the boy had ordered equipment for the pot operation and mistakenly thought the supplies were delivered to Horowitz and Vitale's home, the newspaper reported on its Web site.

The teen went there Saturday looking for the equipment and got in a fight with Vitale, striking her dozens of times in the head with a piece of molding that was left behind at the scene, according to the source.

The boy apparently had scratches on his arms and legs from the fight, the newspaper reported.

If the boy is convicted of murder as an adult, he would face up to life in prison. If convicted as a juvenile, he would be freed on his 25th birthday. He is too young to face the death penalty.

Horowitz said he discovered his wife's body when he returned home after working on the case of Susan Polk (search), a woman accused of stabbing to death her therapist husband.

"She fought back very hard. That was very obvious from the scene," he said Wednesday, adding that his wife had a head wound.

Vitale, 52, worked part-time for her husband's law firm and had been in the front row of the courtroom during opening statements.

Horowitz rose to national prominence as a cable news commentator during the Scott Peterson (search) murder trial. He was in seclusion Thursday as Vitale's memorial service was held in a private graveyard ceremony.