SAN FRANCISCO -- The San Francisco 49ers announced they have signed former Oklahoma State University defensive back Perrish Cox to a two-year contract.

General Manager Trent Baalke said San Francisco is pleased to add Cox to their team.

"As an organization, from ownership on down, we have done our due diligence and are confident that Perrish will be a positive contributor to the 49ers, as well as our community," Baalke said.

Cox recently went through trial and was acquitted of sexual assault charges earlier this month in Colorado.

He was accused of sexually assaulting a woman at his apartment during a party in September 2010. The woman was pregnant and prosecutors reported that DNA tests revealed Cox was the father.

But Cox denied having sex with the woman, and his attorney, Harvey Steinberg, said the DNA test results could have been contaminated.

Cox said he is eager to show his coaches, team and community the type of person he can be.

"I want to thank everybody for giving me the chance to actually express myself to them and to go out and have dinner with the owners and the GM so they can figure out what kind of guy I am," Cox said in a conference call with the Bay Area media, a short time after signing with the 49ers. "I've worked hard through this whole process."

In 2010, the former Cowboy was drafted in the fifth round by the Denver Broncos, and he made significant contributions on both defense and special teams.

He will re-join former Oklahoma State teammate Kendall Hunter, now a running back for the 49ers. The addition is San Francisco's second big signing recently as they also picked up receiver Randy Moss for a one-year deal.