San Gabriel High School was vandalized six months ago, but teachers still don't know what happened with the investigation.
A $20,000 reward is being offered for information that helps identify the suspect.
The Alhambra City Council authorized the reward based on recommendation from the Alhambra Police Department.
The City Council will also consider the South Marengo Ave development and authorizing money for a Rose Parade float.
Alhambra police arrested Ramona Convent Secondary School teacher Diana Yniguez after discovering "sexually graphic text messages" sent by her on her student's phone.
Police had placed San Gabriel High School and Martha Baldwin Elementary School on lockdown late Tuesday morning, before catching fugitive Benedict Romero.
The victim's family says that a sentence of one year in jail and five months probation is too lenient.