Kristin Denise Smart (February 20, 1977 – disappeared May 25, 1996;[1][6] declared legally dead May 25, 2002) was a 19-year-old American woman murdered by Paul Flores at the end of her first year on the campus of California Polytechnic State University, San Luis Obispo (Cal Poly San Luis Obispo).

Smart's disappearance resulted in state legislation, including the Kristin Smart Campus Security Act, a bill which requires all public colleges and publicly funded educational institutions in California to have their security services make agreements with local police departments about reporting cases involving or possibly involving violence against students, including missing students.

[9] At approximately 2 a.m. on Sunday, May 26, 1996, Smart was found passed out on a neighbor's lawn by two fellow students, Cheryl Anderson and Tim Davis, who both had just left the party.

Another student from the party, Paul Flores, joined their group and offered to help the two return Smart to her dorm room.

[13] The University Police Department[14] originally suspected that Smart had gone on an unannounced vacation and as a result were slow in reporting her as a missing person to local law enforcement.

[18] On September 6, 2016, officials from the San Luis Obispo County Sheriff's Office announced they were investigating a new lead in the case.

[19] Cadaver dogs from the FBI were brought in and investigators were preparing to spend approximately four days excavating an area on the Cal Poly campus.

[update][21] On April 20, 2021, prosecutors announced ground-penetrating radar and cadaver dogs found biological evidence indicating Smart's body was once buried beneath the deck of Ruben Flores's home, and had been subsequently exhumed and hidden.

[18] The San Luis Obispo County Sheriff's Office regularly reviewed the case, and spent thousands of hours and dollars during the period 2011–2016.

[25] The FBI had her on file as a high priority missing person investigation, with a reward of $75,000 for information leading to finding her or resolving her case.

Renewed public interest led to a new billboard being put up in Arroyo Grande in January 2020 to replace the original, which had been up since 1997, as well as uncovering several new witnesses.

[32] On February 5, 2020, search warrants were served for "specific items of evidence" at four different locations – two in San Luis Obispo, one in Washington state, and at a home in Los Angeles County.

[34][35][36] On April 22, 2020, the Los Angeles Times reported that a search warrant was served at the home of Paul Flores in San Pedro, California.

[39][40] On February 11, 2021, KSBY reported that Paul Flores had been arrested by the Los Angeles Police Department in Rancho Palos Verdes, California, on suspicion of being a felon in possession of a firearm, which is a felony.

[47] The trial was set to begin on April 25, 2022, but was delayed, as a change of venue motion by the defense was granted on March 30, 2022.

[53] Smart's disappearance and slow response by the campus police resulted in the Kristin Smart Campus Security Act being written and sponsored by State Senator Mike Thompson, passed 61–0 by the California State Legislature, and signed into effect by then-Governor Pete Wilson on August 19, 1998.

The law took effect on January 1, 1999, and requires all public colleges and publicly funded educational institutions to have their security services make agreements with local police departments about reporting cases involving or possibly involving violence against students, including missing students.