I was tempted to call the complex, pretend to be a prospective renter and ask about security provided. But, I didn't.
Abandonment codes:
http://apps.leg.wa.gov/rcw/default.aspx?cite=9A.42
Custodial interference:
http://apps.leg.wa.gov/rcw/default.aspx?cite=9A.40
Possible sentences:
(1) Felony. Unless a different maximum sentence for a classified felony is specifically established by a statute of this state, no person convicted of a classified felony shall be punished by confinement or fine exceeding the following:
(a) For a class A felony, by confinement in a state correctional institution for a term of life imprisonment, or by a fine in an amount fixed by the court of fifty thousand dollars, or by both such confinement and fine;
(b) For a class B felony, by confinement in a state correctional institution for a term of ten years, or by a fine in an amount fixed by the court of twenty thousand dollars, or by both such confinement and fine;
(c) For a class C felony, by confinement in a state correctional institution for five years, or by a fine in an amount fixed by the court of ten thousand dollars, or by both such confinement and fine.
(2) Gross misdemeanor. Every person convicted of a gross misdemeanor defined in Title 9A RCW shall be punished by imprisonment in the county jail for a maximum term fixed by the court of up to three hundred sixty-four days, or by a fine in an amount fixed by the court of not more than five thousand dollars, or by both such imprisonment and fine.
http://apps.leg.wa.gov/rcw/default.aspx?cite=9A.20.021
Unless they find Sky, it looks like she could be facing five years maximum.
ETA: Unless they can somehow state that his disappearance is considered great bodily harm, then she could get up to 10, but I don't think they can stretch that.
If they find evidence of death but no body, they can charge her with murder. I've become a bit obsessed with that no body murder site. We have cases here at WS where convictions are obtained despite no body being found. IIRC most are 2nd degree murder convictions.
Here is one such case here at WS. 4 year old Ashley LaShay Jones has never been recovered but her aunt was convicted of 2nd degree murder in her death.
TN TN - Ashley LaShay Jones, 4, Memphis, 16 Sept 1996 - Websleuths Crime Sleuthing Community
I'm positive LE is testing those swabs for evidence of death which likely occured in the car or apartment. JMO