MARTINEZ -- An Antioch man is facing life in prison without the possibility of parole after jurors convicted him of murdering an Oakland man in broad daylight outside an Antioch shopping center in 2009.

Prosecutors described the victim as a rival of the defendant, but a defense attorney said he was a tormentor who murdered the defendant's son.

A Contra Costa County jury deliberated for about a day and a half before finding Willie Morris Clay II, 46, guilty Friday of first-degree murder with use of a firearm and a special circumstance of lying in wait for killing 46-year-old Gary Lloyd Townsend on April 27, 2009.

Famed Bay Area civil rights attorney Tony Serra argued that Clay should have been convicted of manslaughter in the death of Townsend, who he said was responsible for the killing of the defendant's son, Willie Morris Clay III, in Oakland in 2006 and was out to kill the defendant next.

The two grew up together on the streets of Oakland. Clay became a drug dealer out of necessity, according to Serra, while Townsend became an enforcer for violent crime organizations.

Serra said Townsend escaped justice in killing 30 people by age 28 and numerous others, including an off-duty police officer from Hayward, in the 1990s.

In his closing argument last week, Serra said his client had never killed anyone before he shot Townsend out of self-preservation and fear -- but not revenge -- after spotting Townsend in Antioch, where Clay had moved to lay low and avoid his friend-turned-tormentor after the death of his son and a series of terrifying confrontations.

"He wasn't in his right mind. You wouldn't be in your right mind either if you were haunted and hunted like an animal by this maniac," Serra said.

Deputy district attorney Lynn Uilkema was the prosecutor at Clay's trial but was unavailable to comment on the verdict. Her supervisor, deputy district attorney Mary Knox, who was Clay's prosecutor before Uilkema took over, said Clay killed Townsend because he felt challenged by him.

"This 'I was afraid of Gary Townsend' story was manufactured," Knox said. "Every year he's been in custody, the defense has become more and more dramatic.

"If (Townsend) had killed his son, Willie would have gone after him right after," Knox said.

Knox said Townsend and Clay belonged to the same gang and went into federal custody together for a drug conspiracy. None of the murders the defense attributed to Townsend were proven, and Clay himself has been suspected in multiple murders, Knox said.

Clay testified that he saw Townsend pull into an Antioch shopping center the day of the killing and believed Townsend was there to meet other gang members about a plan to kill him, Knox said, but on cross-examination he admitted to watching Townsend park in front of a prenatal clinic and escort his "very pregnant" girlfriend and her small children inside.

Clay was seen pacing for 28 minutes while he waited for Townsend to exit the clinic, Knox said. After Townsend helped his girlfriend and the children into a car, he got on his motorcycle and began to drive out. He was waiting at a stop sign when Clay ran up from behind and shot him in the head and neck multiple times before sprinting to a car that had its engine running.

Since his arrest, Knox said, Clay has recruited new members for his gang from inside County Jail.

Clay is scheduled to be sentenced Aug. 23.

Contact Malaika Fraley at 925-234-1864. Follow her at Twitter.com/malaikafraley.