SAN FRANCISCO—A man pled guilty to elder abuse for his involvement in the beating and murder of a homeless man in San Francisco’s Golden Gate Park, prosecutors said on Wednesday, February 8.

Robert Tannehill, 36, is one of six people who were arrested for the attack and murder of 66-year-old Stephen Williams.

Williams’ body was found lying face down at Golden Gate Park’s Alvord Lake by a gardener around 7 a.m. on May 24, 2016. The assailants tortured Williams for three days, according to prosecutors.

The victim was beaten and dunked into the Alvord Lake repeatedly on May 22 and three days later he was knocked unconscious and dumped him into the lake.

Five other defendants face felony charges including murder, torture, conspiracy, elder abuse, kidnapping and assault in connection with Williams’ death.

A video surfaced in June 2016 of Williams being taunted, beaten, and tortured by a group of men prior to his slaying in Golden Gate Park, 5 KPIX news reported. The video was shot just two days before the victim’s death.

Tannehill was not charged with murder, but charged with felonies for assault and elder abuse. He is expected to be sentenced on Monday, February 27.

“All human life is precious, and whether you live in a palace or in a park, we will pursue those who resort to violence,” said San Francisco District Attorney’s Office spokesman Max Szabo in a statement last year.