OAKLAND — A man who fatally shot a teenage acquaintance while playing with a handgun two years ago will spend the next 40 years to life in prison, a judge declared Wednesday, agreeing with a prosecutor that the defendant was a career criminal.

Michael Campbell, 21, showed no emotion while he was read his sentence or when family members of Derial Morris Jr. spoke about the pain Campbell caused when he shot the 17-year-old in the forehead.

Campbell, who was 18 when he killed Morris, was found guilty earlier this year of second-degree murder, a crime that usually carries a 25-years-to-life sentence. But Campbell's previous criminal history, which included an auto theft and a robbery, allowed Alameda County Superior Court Judge Leo Dorado to issue a harsher penalty.

"Mr. Campbell has earned his 40 years in state prison," Dorado said.

Campbell shot Morris on April 18, 2007, while he was in an apartment in the Acorn housing project telling a group of people a story while his finger was on the trigger of a gun. At one point he mistakenly pulled the trigger, firing a bullet into Morris' forehead, instantly killing him, authorities said.

After the killing, Campbell and several others in the apartment put Morris's body in a shopping cart, wheeled him into an elevator and placed him in a car with the intention of taking Morris to Highland Hospital, Deputy District Attorney Melissa Krum said.

However, Campbell never made it to

When Campbell was arrested a month later, police said, he showed no remorse for the killing and laughed while he was being questioned by police. Campbell also resisted arrest, causing a seven-hour standoff that ended after police fired tear gas into his home.

Morris's family members said they also saw Campbell laughing during the trial.

"Every time the judge walked out of the courtroom, you turned and laughed like this was some kind of joke," said Anita Morris, the victim's mother. "Whatever you get in jail, you deserve it. Every time you go for parole, you are going to see me. I am going to be your worst nightmare."

Although Campbell claimed he was friends with Morris, Anita Morris said Campbell was, at most, an acquaintance of her son.

Cecelia Bell, Morris's grandmother, said Campbell deserves to spend the rest of his in prison.

"I hope you suffer for what you did to my grandson," she said. "You seem to think this is funny but laugh when you go to prison."

Aundrea Brown, a deputy public defender who represented Campbell, said the entire event was tragic.

"It's a sad day," she said. "It is sad to see kids that are killed, it's sad to see kids go away for the rest of their lives."