From Jan. 1 to April 30, police received reports of 59 sexual assaults against adults - up from 33 during the same period in 2008, said Sgt. Norm Leong.
Some of those reported attacks have been determined to be unfounded, Leong said, but the overall trend still has been upward.
The news is alarming, though not surprising, said Beth Hassett, executive director of the nonprofit group Women Escaping a Violent Environment.
She said WEAVE advocates accompanied 492 victims during their exams in Sacramento County hospitals last year - and, because sexual assault is an underreported crime, Hassett said, the actual number of victims is probably much greater.
"It's very challenging to get survivors to report the crime, and we too often end up working with them years down the road when there's been a lot of post-traumatic stress syndrome," she said.
Reporting the assault immediately also allows victims to get better health care for consequences such as sexually transmitted diseases or unintended pregnancies, Hassett said.
In addition, immediate reporting of a crime can help ensure a successful criminal case against the attacker, Leong said. He encouraged victims to avoid showering prior to an exam and to keep the clothes worn during the attack.
Though assaults by acquaintances can be more difficult to prevent than those by strangers because of the element of trust, Hassett said women should "really trust their gut instinct" when they feel uncomfortable or frightened.
Excluding sexual assaults, Leong said crime statistics from the first quarter of 2009 are down from the same period in 2008.
Homicides in particular are down dramatically this year: there were just six by April 30 compared with 16 in the same period last year.
The other good news: sexual assaults are down in the Sacramento County sheriff's jurisdiction. There were 214 sexual assaults - including crimes against children - reported to date this year, down from 262 in the same period in 2008, said Sgt. Tim Curran.
