OAKLAND -- The consequences of the city's burgeoning crime rate were evident at the Rene C. Davidson Courthouse on Friday as four convicted murderers, none older than 24, were sent to prison.

All but one of the killers will most likely never be released, while the fourth must serve at least 15 years as part of a plea deal in which she admitted committing second-degree murder.

Even more disturbing, the unrelated murders were sparked by mostly trivial matters, including a fight over a girl, a disrespectful comment and a robbery gone bad.

"It's frightening, and it is very upsetting," said Alameda County Superior Court Judge Joan Cartwright as she sentenced Marcus Ward, 23, to life in prison without the possibility of parole. "You have total lack of respect for anything."

A similar scene played out in two other courtrooms as Judge Vern Nakahara sent Casey Turner, 18, to prison for 84 years to life, and Judge Jon Rolefson sent Michael Peau, 24, to prison for 50 years to life.

"It's sad that all these young people are out there living in the wild, wild, West," said deputy district attorney Butch Ford, who prosecuted Turner. "These are the repercussions. You have one young man dead and another spending the rest of his life in prison."

Turner was found guilty of killing James Allen Jr., 18, during a gunfight across a busy 90th Avenue in the middle of the day on March 27, 2010.

The fight began, evidence in the trial revealed, after Turner, who was 15 years old at the time, and Allen Jr. were fighting over a girl they had dated.

Turner shot across the street at Allen Jr. and two of his friends as the trio walked out of a passageway of an apartment building at 2124 90th Ave. In addition to being found guilty of second-degree murder, Turner was found guilty of two counts of attempted murder and using a gun causing death, a crime that carries a sentence of 25 years to life.

Turner showed no emotion as Nakahara sent him to prison for life.

Ward, however, said he didn't care about being sent to prison for life as Cartwright lectured the 23-year-old.

"Can you hurry up, 'cause I don't care," Ward said as Cartwright spoke.

Ward was found guilty of a special circumstances murder for killing Michael Schenk, 31, during a robbery. Ward devised a plan to rob Schenk, a pimp, with his girlfriend, Gequesha Nolan, 22, who was also a prostitute.

The killing occurred on Oct. 5, 2011, as Schenk sat in his car on Favor Street. Nolan took a plea deal in which she admitted committing second-degree murder and was sentenced to 15 years to life Friday.

Ward, however, was not offered a deal, and a jury found him guilty in less than two hours after a weeklong trial.

A jury deciding the face of Peau also took little time in rejecting his claims that he killed Roberto Guzman Jr., 20, in self-defense on Sept. 24, 2011. Peau said that Guzman tried to attack him with a screwdriver in the middle of a West Oakland street around noon.

Deputy district attorney Luis Marin, however, presented evidence showing that Peau intentionally killed Guzman because he was upset that Guzman told him to leave his family alone. Guzman was upset with Peau because the one-time family friend had sold Guzman's father a stolen car, which almost led to the father's arrest.

At a party before the shooting, Guzman told Peau to stay away from his family, a request that angered Peau, who told others that he was disrespected.