A former private investigator and Antioch police officer who pleaded guilty to seven felony charges for his role in a Contra Costa County law enforcement scandal was sentenced Tuesday to eight years in federal prison.

U.S. District Court Judge Saundra Armstrong sentenced Christopher Butler,50, in association with the so-called "Dirty DUI" scheme that included drug offenses, conspiracy, extortion and illegal wiretapping. The sentence was four and a half years less than the 12.5-year term recommended by federal probation officers.

Butler's attorney, William Gagen, admitted after the hearing that the light sentence for Butler was "a substantial departure" from federal sentencing guidelines for the crimes for which he was convicted.

But Gagen pointed out that the eight-year term was recommended by the U.S. Attorney's Office because but he said he believes the outcome was "very justified" because of what he described as Butler's "extraordinary" cooperation with prosecutors since he was arrested last year.

"From day one everything he said has been factually accurate and corroborated," Gagen said. "That's whey the government really did go to bat for him."

Butler pleaded guilty on May 4 in connection with drug possession and sales, robbery, conspiracy against civil rights, extortion and other crimes he committed as a private investigator working with members of the Contra Costa County Drug Enforcement Team (CNET) over a period of about
four years.

Among the others who have been charged in connection with the corruption are former CNET Cmdr. Norman Wielsh, 50, former Contra Costa Sheriff's Deputy Stephen Tanabe, 48, former San Ramon police Officer Louis Lombardi, 39, and San Ramon divorce attorney Mary Nolan, 60.

Lombardi was sentenced in May to three years in federal prison in exchange for admitting his theft of more than $40,000 during searches of
suspects' homes.

Nolan, who was arrested last week, pleaded not guilty at a brief court appearance in federal court Tuesday to charges of evading taxes and conspiring with Butler.

Wielsh and Tanabe have also pleaded not guilty and are awaiting trial on the charges against them.

In his guilty plea, Butler said that between June 2009 and February 2011, he teamed with Wielsh to sell large quantities of marijuana, methamphetamine and steroids obtained during CNET searches of suspects' homes.

Working with an employee in his Concord private investigation firm to sell the drugs, Butler and Wielsch split the proceeds, which totaled no more than about $30,000, according to Gagen.

On several occasions, Butler drove Wielsh to the Contra Costa County Sheriff's Office evidence facility to take drugs from lockers and keep them for sale, Butler told the court.

The private investigator also admitted to conspiring with Wielsch to stage illegal search-and-seizure operations of prostitutes the CNET commander found via online ads on websites such as Craigslist.com and Redbook.com.

The pair met the prostitutes at hotels in San Ramon and throughout the Bay Area, with Butler acting as the john. After knocking on the door,
Wielsh would burst in the room, show his police badge and seize the woman's possessions and cash, Butler said.

Butler also pleaded guilty to helping Wielsh in 2009 open an illegal massage parlor where the masseuses provided sexual services. He admitted today to collecting more than $10,000 from the women working there in exchange for protection from Wielsh.

Addressing allegations of illegal wire-tapping, Butler described how he illegally installed between 75 and 100 listening devices in the
vehicles of his clients' spouses to secretly record their conversations for his clients and their attorneys.

Butler also admitted to working with Tanabe to stage drunken-driving arrests of his clients' spouses, who were often involved in custody battles or other legal disputes.

As part of his plea agreement, Butler agreed to testify if asked against Wielsh and Tanabe if their cases go to trial.

Before he was sentenced, Butler, a bald, bespectacled man who was dressed in light brown jail clothes, said, "I apologize to the community for the anxiety, fear and suffering I caused others and to the law enforcement community for the embarrassment and betrayal I inflicted on it."

Butler said he also apologizes "to my friends and family who supported me through all of this."

Gagen said Butler has been taking philosophy courses and other subjects through Holy Names University in Oakland since he was arrested and has maintained a 4.0 average.

Gagen said Butler "is genuinely sorry" for the crimes he committed and predicted, "when he gets out of prison he will be a very different man."

The defense lawyer said Butler is in protective custody 23 hours a day at the federal prison in Pleasanton because of concerns that other inmates might target him because he's a former police officer and is considered "a snitch" because he has promised to testify against the other suspects in the case.

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