(a) In the course of the 72-hour evaluation period, a petition for commitment to a treatment facility may be filed in court. The petition must be signed by two mental health professionals who have examined the respondent, one of whom is a physician. The petition must

(1) allege that the respondent is mentally ill and as a result is likely to cause harm to self or others or is gravely disabled;

(2) allege that the evaluation staff has considered but has not found that there are any less restrictive alternatives available that would adequately protect the respondent or others; or, if a less restrictive involuntary form of treatment is sought, specify the treatment and the basis for supporting it;

(3) allege with respect to a gravely disabled respondent that there is reason to believe that the respondent's mental condition could be improved by the course of treatment sought;

(4) allege that a specified treatment facility or less restrictive alternative that is appropriate to the respondent's condition has agreed to accept the respondent;

(5) allege that the respondent has been advised of the need for, but has not accepted, voluntary treatment, and request that the court commit the respondent to the specified treatment facility or less restrictive alternative for a period not to exceed 30 days;

(6) list the prospective witnesses who will testify in support of commitment or involuntary treatment; and

(7) list the facts and specific behavior of the respondent supporting the allegation in (1) of this subsection.

(b) A copy of the petition shall be served on the respondent, the respondent's attorney, and the respondent's guardian, if any, before the 30-day commitment hearing.