TULSA, Oklahoma - A former group home manager said a weekend assault at a Tulsa park could have been prevented. He said the man accused of committing lewd acts against a child should have never been at the park unsupervised.

Police arrested Richard Peters at Reed Park Saturday evening after witnesses told police they saw him trying to sexually assault a 13-year-old girl and her 11-year-old sister.

Two men stepped in to help the girls and held Peters until police arrived.

Peters apparently had no business being outside his group home, now the 37-year-old is in the Tulsa County jail facing charges for attempted lewd molestation of a child, kidnapping and two counts of child abuse.

"I felt that was just a shame. Kids out here trying to enjoy the nice weather then some random guy just comes up and decides he wants to start trouble with these young ladies," said concerned parent Carl Peterson.

Police documents say Peters attempted to force his hands under a 13-year-old girl's shirt and pants as her 11-year-old sister stood nearby.

The arrest report says Peters admitted that “he forcibly grabbed the victim by her neck and forced her to the ground, holding her while she screamed while he attempted to have sex with her."

Peters’ former group home supervisor said, "This was preventable, entirely and completely preventable."

The man said he used to supervise Peters when he worked as a house manager at a Sapulpa group home.

"Some of them can have alone time, some of them can be in the public alone - Richard Peters wasn't one of those. He had to constantly be followed, even in the grocery store," the man said.

He said with Peters’ mental condition and history of violence, he should have never been anywhere near the park by himself.

Police documents say Peters is a bi-polar schizophrenic.

At the time of his arrest, police said he was living at a group home in Tulsa, but when we tried to talk to a man inside he shut the door on us.

"I would like to know why he was not watching this man at this time cause that's his job," the man said.

We called the company we're told oversees the group home where Peters lived. So far we haven't heard back from them.

Peters is being held on a $175,000 bond.