DETROIT (WWJ/AP) - The former head of Detroit’s water department has pleaded guilty, six weeks into a corruption trial that also involves ex-Mayor Kwame Kilpatrick.

Former water department director Victor Mercado on Monday pleaded guilty to conspiracy to commit extortion before federal court judge Nancy Edmunds.

Mercado, 61, never took a bribe or kickback but couldn’t resist pressure from Kilpatrick to help Bobby Ferguson, who owned a construction company, Assistant U.S. Attorney Mark Chutkow said.

“He was a reluctant participant in this conspiracy. … He did from time to time push back but compromised himself,” Chutkow told the judge.

The prosecution will be seeking a maximum of 18 months in prison.

Said WWJ Legal Analyst and Talk Radio 1270 host Charlie Langton, “What this means, first of all … the jury is not gonna see one of the four gone right now and so they’re already, in the mind of the jury, the jurors are gonna say, ‘What happened to this person?’ It’s unlikely that he got off, so they’re gonna think that he took a plea.

“Also, too, he could not, Victor Mercado, he could now be a witness against these three,” said Langton. “Now the government’s got a witness, a strong witness, that can give absolute testimony against these three … possibly not Bernard Kilpatrick, but certainly Kwame Kilpatrick and Bobby Ferguson.”

Langton called this a “bad day” for Kwame Kilpatrick, but Wayne State University Legal Expert, Peter Henning said he doesn’t think Mercado will be called to testify.

“One problem is, his lawyers presented him as not guilty of the charges and if he was brought in as a witness he would, of course, have to admit that he was guilty and could send a bad message to the jury, that he’s talking out of the both side of his month,” Henning said. “So, I expect this plea deal is designed mainly to make the government’s case a little bit easier. Victor Mercado was more of a distraction.”

As for whether this may pressure the other defendants to plead guilty, Henning said it’s unlikely.

Outside court, defense attorney Martin Crandall said the possible punishment is significantly lower than what Mercado could have faced if he had been convicted at trial.

“It’s a good decision at the right time,” Crandall said.

The trial has been dominated by testimony about payoffs and fraud involving Kwame Kilpatrick and Ferguson. The allegations go beyond the water department and date back to 2000 when Kilpatrick, as a state lawmaker, lined up public grants for a nonprofit group led by Ferguson.

Kilpatrick defense lawyer James Thomas shrugged off Mercado’s guilty plea, insisting “it doesn’t mean anything” for his client.

Sentencing for Mercado won’t take place until after the trial, which could stretch into the new year. The trial is in recess until next week because of a lawyer’s illness.

Kwame Kilpatrick resigned from office in 2008 and pleaded guilty to obstructing justice by lying in a civil case about having sex with an aide. He subsequently served 14 months in prison for violating his probation in that case.

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