San Francisco 49ers kicker David Akers said Thursday he received death threats on Twitter and closed the account. He received the threats last month, but was unsure at the number because he did not go further back on his account to count.

Once he saw them, he reported it to team and N.F.L. security personnel. The 49ers said they were aware of the situation, as was the league. Akers has been in a slump compared with 2011, when he made 44 of 52 field goals. This season he is 29 for 42.

PLAYER IN CRASH WAS SOBER An autopsy has found that Dallas Cowboys practice squad player Jerry Brown Jr. was sober when he was killed in a crash that led to an intoxication manslaughter charge against the teammate at the wheel.

The Dallas County medical examiner’s office reported that Brown died of head and neck trauma when their vehicle overturned. He had a blood alcohol content of 0.056 percent. That is below the Texas drunken driving standard of 0.08 percent.