OAKLAND -- When Angelique Arvizu met Lamont Couch, she quickly noticed he was driving a Mercedes-Benz and carrying a large amount of cash.

Arvizu, 22, soon told her boyfriend Darrell Smith, 25, about Couch and together they plotted a robbery scheme in which Arvizu would lure Couch to an area where Smith and his friend, Jeffrey Simpson, 24, would be waiting.

While the three said they never intended to harm Couch, 34, the opposite happened. Couch, a former City of Oakland employee, was shot during the robbery attempt and died hours later.

Now Arvizu, Smith and Simpson face decades in prison after reaching plea deals with the Alameda County District Attorney's Office just as their trial for murder was about to begin in Judge Vern Nakahara's courtroom.

Deputy District Attorney Tim Wellman said his case against the three Oakland residents was strong and included taped confessions each gave police and text messages from their phones that shows them plotting the robbery.

Yet, Wellman said, he accepted the plea deals because they will result in each defendant paying handsomely for their crimes and brings a certain end to a tragic case. The three defendants also waived their right to appeal as part of the deals.

"It was a strong case that I wasn't looking to resolve (through plea deals)," Wellman said. "On the other hand, the offers the defendants were willing to agree to were sufficient to hold them accountable for what they did."

Attorneys representing the three defendants could not be reached for comment.

The killing occurred after Arvizu went on a date with Couch on April 15, 2011. The couple went to a club and then afterward, Couch drove Arvizu to the 6900 block of Halliday Street where Arvizu had her car parked.

Also waiting on the block were Smith and Simpson.

After Arvizu got in her car and began to drive away, Smith and Simpson ran up to Couch and tried to rob him. Couch fought back and, in the process, batted away a pistol in Simpson's hand and the weapon fell to the ground. A struggle ensued and then ended after Smith grabbed the gun and handed it to Simpson who fired a single shot into Couch's back.

Couch drove away but crashed his car into a metal fence that surrounded a nearby home. He eventually died from the gunshot wound.

Oakland police solved the case by checking Couch's cell phone and tracing Arvizu's phone number through text messages that showed she and Couch were together before he died. When Arvizu was brought in for questioning, she admitted to the robbery plot and killing.

Simpson will receive the harshest penalty of the three because he is the person who brought a 9 mm handgun to the robbery and the one who shot Couch in the back.

As part of the deal, Simpson, who faced life in prison without the possibility of parole had the case gone before a jury, was instead found guilty of first-degree murder and personally using a firearm causing death. He will be sentenced to 45 years to life and must serve 45 years before he is eligible for parole.

Smith was found guilty of second-degree murder with an enhancement of being armed with a gun. Smith will be sentenced to 23 years to life in prison and will not be eligible for parole until after serving 23 years.

Arvizu was found guilty of second-degree murder with an enhancement of being armed with a gun. She will be sentenced to 16 years to life in prison and must serve 16 years before she is eligible for parole.