Witnesses Say Slain Boy Had Been Sexually Abused : Hearing: A jail inmate testifies that Gregory Smith confessed to killing the Northridge child.

Witnesses testified Thursday that an 8-year-old Northridge boy whose burned body was found in Simi Valley last spring had been sexually assaulted, and that his accused killer had a history of molesting boys.

A day of dramatic testimony in Ventura County Superior Court began with Mary Bailly’s last memories of her slain son, Paul, and ended with a jailhouse informant’s tearful account of Gregory Scott Smith’s alleged confession to the boy’s slaying.

Mary Bailly left Paul at the front door of his day-care center in Northridge a few minutes after 7 a.m. on March 23, 1990, and never saw him again, she testified at Smith’s preliminary hearing.

A few months earlier Paul had asked if he could go to the store with Smith, Bailly testified.

“And I told him he should never go with anyone, ever, and he should never leave the school, ever,” Mary Bailly testified, her voice calm and her eyes dry. “He understood.”

The preliminary hearing, which continues today, is the second for Smith, 23, of Canoga Park.

Prosecutors had to throw out the first preliminary hearing and refile charges against Smith after a fellow Ventura County Jail inmate, Tracy Prell, told them that Smith had confessed the slaying to him.

Prell’s accounts led prosecutors to have an expert on child abuse re-examine Paul’s autopsy, and to add charges of sexual assault to the charges of kidnaping, murder and arson Smith already faced.

On Thursday morning, Dr. Bruce A. Woodling, who said he has treated 2,500 cases of child abuse, testified that autopsy photos showed that Paul was sexually molested before his body was set afire.

On Thursday afternoon, Prell took the stand.

He testified for nearly three hours, saying that he crossed his fingers behind his back when Smith made him swear not to tell anyone of their conversations about Paul’s death.

On Dec. 10, Smith returned to his cell next to Prell’s, angry that prosecutors learned that he might have suffered brain damage in a near-drowning during his childhood, Prell testified.

Prell said Smith then said of the crime, “I was obsessed. It was like a dream. I did it. I was obsessed. It was like a dream. I did it.”

Prell said Smith told him that he took Paul from the day-care center the child attended at Darby Elementary School to a remote field in Simi Valley and pulled the boy out of the car. “He said he yanked him up and put a gag on his mouth cut from some blue boxer shorts, and stuffed it down his throat,” Prell testified, as Mary Bailly and Smith’s mother, Sherron Smith, looked on.

“He threw Paul in the trunk of the car,” Prell continued, under direct examination by Deputy Dist. Atty. Peter D. Kossoris. “He then proceeded to go back to the school, but somewhere along the line. . . he looked in the trunk and seen the body was dead.”

Prell said Smith told him that Paul had “drowned on his own throw-up, the gag was in his mouth still. He panicked. He turned around and went to the crime site. He threw the body out and poured gasoline on it. He lit the matches and it went up in flames. . . . He wanted to destroy the evidence.”

Prell, in County Jail for battery, resisting arrest and violating probation, testified that he said nothing to Smith because the conversation “was blowing my mind away.”

At this, Judge John E. Dobroth called for a recess. Prell stepped into the empty jury box and sank into a seat, crying.

Moments later, Prell retook the stand, testifying that Smith told him that he had been having sexual relations with a 20-year-old friend named Derek since he was 10.

“He told me he had sexual urges when Derek wasn’t around, that he’d go out and molest little boys,” which included boys aged 4, 4 1/2 and 9 from an unidentified day-care center in the San Fernando Valley.

Prell said his testimony against Smith was not in exchange for any leniency or shortened sentence, and that he had decided to take the stand because he has a 3-year-old son and put himself in the “position of what Mrs. Bailly was feeling at the time.”

Under cross-examination by defense attorney James M. Farley, Prell admitted that he had been treated with unknown drugs at the jail infirmary 10 days ago because he was hearing voices. “I was probably just stir-crazy at the time,” he said. But other witnesses corroborated some of Prell’s testimony.

Sherron Smith testified that she found the pair of blue boxer shorts in her washing machine, from which prosecutors say Smith had cut the cloth gag.

Derek Trexel, 21, testified that he began engaging in sexual play at age 6 with Smith, then 8, when the two were in the first grade at Enadia Way School in Canoga Park, which he described as “a school for hyperactive children.”

The last time the two had sex was one or two months before Smith’s arrest on March 24, Trexel said.

Smith’s arrest came just three weeks after he was fired from the Darby Elementary School day-care program that Paul attended, testified Harold Kuhn, director of latchkey services for 31st District Parent Teacher Student Assn. in the San Fernando Valley.

Kuhn testified that he fired Smith on March 6 for leaving the children unattended and disciplining them too harshly.

Prosecution testimony in the preliminary hearing is scheduled to continue today.