He began talking to the 49ers on Monday, then visited team headquarters Wednesday.
"It just seemed like a good change of scenery. I've known Coach Harbaugh pretty much my whole life," Edwards said.
"I think I've put myself in some situations I'm to blame for and coming out here is a good, fresh start to get clean personally with people that I trust and with a team that's supporting me through what they know I'm going through," he said.
"When he played there and when I played there, we were taught how to be accountable, responsible, to know right from wrong. That's what I want to get back to, being the guy that can be accountable, that can be respected and who can be put in a position to thrive here and be a responsible guy for this organization."
Safety Donte Whitner also said on Twitter that he has joined San Francisco, then sent a tweet to Edwards.
"Bray I signed there today also...let's get a RING!"
The 26-year-old Whitner, the eighth overall pick out of Ohio State in 2006, ranked fifth in the NFL with 140 tackles last season for Buffalo and also had one forced fumble, an interception and half a sack. He apparently had been close to signing with the Cincinnati Bengals.
With the addition of Edwards, the Niners now have the No. 1 (Smith), No. 3 (Edwards) and No. 9 (cornerback Carlos Rogers) overall picks from the '05 draft.
Second-year safety Taylor Mays, a second-round draft pick out of Southern California last year, was on the field for practice amid reports the 49ers are reaching out to teams across the league in an effort to trade him.
Harbaugh acknowledged the 49ers have received inquiries about Mays over the past eight days.
Harbaugh said general manager Trent Baalke spoke to Mays.
"Taylor's a 49er," Harbaugh said. "There have been inquiries over the last eight days, enough to the point where you say, 'Let's check it out.' That's where we're at."
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