OAKLAND -- An ex-cop turned private investigator at the center of a Contra Costa police corruption scandal was sentenced to eight years in federal prison and ordered to pay a $20,000 fine Tuesday for crimes that brought down a Department of Justice vice squad and led to the prosecution of officers from three law enforcement agencies.

"(I want to) apologize to the community for the anxiety, fear and suffering I have caused others. I want to apologize to the law enforcement community for the betrayal and embarrassment I inflicted upon it. I want to apologize to my family and friends who supported me through all of this," Christopher Butler said, his voice breaking.

He pleaded guilty in May to seven felony counts covering methamphetamine and marijuana distribution, theft, conspiracy, extortion, robbery and illegal wiretapping.

Butler, 51, was sentenced a few hours after San Ramon family law attorney Mary Alice Nolan pleaded not guilty to tax evasion and other felony charges alleging that she and Butler bugged the cars of her clients' estranged spouses to get dirt that she could use in divorce and child custody cases.

Butler received a punishment that's four years less than the minimum called for under federal sentencing guidelines based on his cooperation with the government since he was arrested alongside Contra Costa Narcotics Enforcement Team (CNET) Commander Norman Wielsch in February 2011 in the stealing and reselling of thousands of dollars worth of illicit drug evidence. The investigation ballooned to include allegations that the pair made phony arrests, robbed prostitutes and ran a Pleasant Hill brothel.

Butler's attorney William Gagen said it was through Butler's confession, all of which was corroborated, that investigators learned of certain crimes by law enforcement officers and Butler himself. An Antioch officer before he opened the Butler & Associates private investigation firm in Concord, Butler began committing crimes a few years ago to make money when he went broke pursing fame through his failed reality TV project, "P.I. Moms," which he promoted on the national talk show circuit and in People magazine, Gagen said.

Butler told authorities that on up to 100 occasions over the past decade, he was paid by attorneys and their clients to place illegal eavesdropping devices in the cars. Butler also admitted to setting up the estranged spouses of clients for drunken-driving arrests, including two men whose ex-wives were represented by Nolan and are now suing her and the former P.I. in civil court.

Prosecutors said at least five men fell victim to the so-called Dirty DUIs scam in which attractive women employed by Butler would get the men drunk and behind the wheel before a waiting Butler would tip off patrol officers.

Nolan, a 60-year-old Oakland resident, was heckled by a client's former partner as she rushed from the Oakland federal courthouse after the hearing. Her attorney, Jay Weill, said he was not commenting on the case.

"This is Christmas, to see her stand in front of a judge," said Phil Dominic, who alleges Nolan lied about financial information and used stalling tactics when she represented his son's mother in an Alameda County Superior Court child support case.

Dominic, 55, of Oakland, said Nolan twice tried to buy from him oxycodon he's prescribed for pain while he awaits a hip replacement. He said a judge dismissed his allegations because he was convicted of robbery in the 1980s and Nolan is an officer of the court.

"I told her, one day you are going to end up in jail," Dominic said.

Prosecutors on Tuesday reserved the right to reduce Butler's sentence based on any future testimony he may give in the criminal cases pending against Wielsch, Nolan and former Danville officer Stephen Tanabe.

Tanabe, charged in the Dirty DUI scheme, asserts he's innocent and is awaiting trial. Wielsch has admitted to some alleged crimes but denies others, and is awaiting a January trial.

Former San Ramon officer Louis Lombardi was sentenced in May to three years in federal prison after pleading guilty to charges that he stole at least $40,000 in cash, as well as guns, jewelry and other property, while executing search warrants as a police officer and as an agent for CNET. Nolan faces up to 15 years in prison under her indictment, handed down by a federal grand jury earlier this month.

Contact Malaika Fraley at 925-234-1684. Follow her at Twitter.com/malaikafraley.