Updated

A judge on Friday ordered four life sentences for an honor student and former Boy Scout who shot his parents and brothers to death, then went to a friend's house to play video games.

Baltimore County Circuit Judge Thomas Bollinger ordered Nicholas Browning, 16, to serve two of the sentences consecutively and two concurrently. He could be eligible for parole in 23 years with good behavior.

Browning wrote a statement in which he apologized to his family, but he was overcome with emotion and wasn't able to read it in court. The only words he managed to speak were, "I'm so sorry."

Prosecutors requested the four life terms for Browning after he pleaded guilty in October to first-degree murder in the deaths of his parents, John and Tamara, and his younger brothers, Gregory and Benjamin.

Prosecutors never disclosed a motive, but in a court filing Thursday defense attorneys offered their first explanation, saying the killings were the "result of years of abuse suffered by Nicholas Browning" at the hands of his alcoholic father.

The teen "had been battered and beaten to the point where his immature juvenile mind could conceive of no other alternative to relieve the pain than to eliminate it," according to the defense memorandum. Browning's family members have declined comment on the case.

Assistant State's Attorney Leo Ryan Jr. said in court Friday that the abuse allegations do not explain why Browning would kill his younger brothers. Prosecutors played portions of a police interview in which Browning, who at the time claimed innocence, said a big inheritance and life insurance payments were coming his way.

Browning's attorneys had asked that he serve all four life sentences at once to give him a better chance of one day reuniting with his extended family.

Bollinger rejected that request but recommended that Browning be referred to the Patuxent Institution, a psychiatric center with a program for youthful offenders.

In Browning's statement, read aloud Friday by defense attorney Joshua Treem, the teen thanked his relatives for showing him "unconditional love" and said he was thinking only of himself at the time of the killings.

The victims were shot as they slept in February in the family's home in Cockeysville, a Baltimore suburb.