The Supreme Court has again reinstated the conviction of a California woman for shaking her 7-week-old grandson in a case that has become a tug-of-war with the federal appeals court in San Francisco.

Shirley Ree Smith was convicted in December 1997 and was sentenced to 15 years to life in prison.

After California appeals courts ruled against Smith, the 9th U.S. Circuit Court of Appeals overturned the conviction in 2006. The appellate judges said they found "no demonstrable support" for the prosecution's theory of the case. Prosecutors said that Smith lost her temper when Etzel Dean Glass III began to cry and shook him to death.

In 2007, the high court ordered the 9th Circuit to reconsider its decision based on a recent Supreme Court ruling. In that case, the justices overturned another ruling by the appeals court that was favorable to a convicted killer.