The 26-year-old was shot and killed while on duty last week.
RELATED: Who was Officer Tara O'Sullivan?
Body camera footage from her training officer, shows what the Sacramento Police Department is calling an ambush on Officer O'Sullivan and others on scene who were trying to help a woman out of an alleged domestic disturbance.
"We lost someone whom we love, someone who put her life on the line for someone who needed her," said Robert Nelsen, the president of Sacramento State University. He knew O'Sullivan well.
She was the first female graduate of the Law Enforcement Candidate Scholars' Program.
"To watch her take control of all those guys, she stood out. She was a leader and you could tell that right from the beginning," said Nelsen.
O'Sullivan is originally from the Bay Area.
RELATED: 'She was living her values,' Sacramento mourns loss of young police officer
She graduated from College Park High School in Pleasant Hill.
Her family lives in Martinez and her parents wore t-shirts to the vigil that said "trust"... "together we build," with a police badge.
In honor of Officer O'Sullivan, blue bows have been tied around Sac State - a temporary reminder of her presence on campus.
More permanently, the university has set up a scholarship in her name for the Law Enforcement Candidate Scholars' Program, cementing her legacy at the school.
You can make a donation to Officer O'Sullivan's memorial fund here.
Female officers from Sacramento PD and law enforcement agencies all over the region walk into a vigil - holding hands - for Officer Tara O’Sullivan who was shot and killed on duty last week. 💙 Tara was a Sac State graduate. 💚 pic.twitter.com/gdgn4ehQt3— Kate Larsen (@KateABC7) June 24, 2019
Officer Tara O’Sullivan, 26, grew up in the Bay Area. She graduated from College Park High School in Pleasant Hill. Her parents and family live in Martinez. Tonight, they are wearing shirts that day “trust” with a police badge on the front and “together we build” on the back. 💙 pic.twitter.com/0jrW9iH4r1— Kate Larsen (@KateABC7) June 24, 2019
Officer Tara O’Sullivan, is the 2nd cop killed in the region this year. In January, Officer Natalie Corona was shot and killed in Davis.— Kate Larsen (@KateABC7) June 24, 2019
Tonight, you can see and feel the pain and suffering, but also the love and resiliency from these female law enforcement professionals. pic.twitter.com/flRtT96axi