Boston police say they spent nearly $750,000 on officer overtime during the trial of Boston Marathon bomber Dzhokhar Tsarnaev.

Police officials said Thursday that officers worked more than 13,000 hours of overtime helping secure the federal courthouse from January through May during the trial and on June 24 when Tsarnaev was sentenced to death. The total bill was about $748,400.

The two bombings by Tsarnaev and his brother, Tamerlan, near the marathon's finish line on April 15, 2013, killed three people and wounded more than 260. Tsarnaev also was convicted of killing MIT Officer Sean Collier during the getaway. Tamerlan died after a shootout with police in Watertown.

Costs for other law enforcement agencies that guarded the federal courthouse during Tsarnaev's trial weren't immediately available.