In the Philippine legal system, physical assault is generally prosecuted under the Revised Penal Code (RPC) as Physical Injuries. However, when the victim or the perpetrator is a person with a mental disability, specific procedural safeguards, protective laws, and evidentiary rules come into play to ensure "access to justice" as mandated by the 1987 Constitution and the Magna Carta for Persons with Disabilities (R.A. 7277).

1. Classification of the Offense

Depending on the severity of the wounds and the period of medical attendance required, physical assault is categorized under the RPC as:

Slight Physical Injuries (Art. 266): Healing period of 1 to 9 days.
Less Serious Physical Injuries (Art. 265): Healing period of 10 to 30 days.
Serious Physical Injuries (Art. 263): Healing period exceeding 30 days, or resulting in deformity, loss of a limb, or permanent disability.

Special Aggravating Circumstance: Under R.A. 9262 (VAWC) or R.A. 7610 (Child Abuse), if the victim is a woman or a child with a mental disability, the penalties are typically increased to their maximum period.

2. The Preparatory Stage: Filing the Complaint

The process begins with the filing of a Complaint-Affidavit.

Where to File

Philippine National Police (PNP): Specifically the Women and Children Protection Desk (WCPD), which is trained to handle vulnerable sectors, including those with mental disabilities.
National Bureau of Investigation (NBI): For more complex cases.
Office of the City/Provincial Prosecutor: For the direct filing of a complaint for Preliminary Investigation.

Key Documents Needed

Complaint-Affidavit: A sworn statement detailing the assault.
Medical Certificate: Issued by a licensed physician (preferably a government doctor) detailing the injuries.
Psychiatric/Psychological Evaluation: To establish the mental disability of the victim or the state of the perpetrator.
Barangay Blotter: While not always mandatory, it serves as initial evidence of the incident.

3. The Preliminary Investigation

Once the complaint is filed with the Prosecutor’s Office, a Preliminary Investigation (PI) is conducted to determine Probable Cause.

Subpoena: The respondent (the accused) is issued a subpoena to submit a Counter-Affidavit.
Resolution: The Prosecutor decides whether there is sufficient ground to believe a crime was committed.
If Yes: An "Information" (criminal charge) is filed in court.
If No: The case is dismissed, though this is appealable via a Motion for Reconsideration or a Petition for Review to the Department of Justice (DOJ).

4. Special Considerations for Mental Disability

The "Competency" of the Witness

Under the Revised Rules on Evidence, a mental disability does not automatically disqualify a person from testifying. As long as the victim can perceive and make their perception known to others, they are a competent witness.

The Rule on Examination of a Child Witness

If the victim is a minor with a mental disability, the court applies the Rule on Examination of a Child Witness. This allows for:

Support Persons: A facilitator or psychologist can sit near the victim.
Live-Link TV: Testimony via a remote feed to prevent "re-traumatization" by seeing the accused.
Hearsay Exception: Statements made by the disabled victim to a third party (like a therapist) may be admissible as an exception to the hearsay rule.

The Defense of Insanity

If the accused has a mental disability, they may invoke Article 12 of the RPC (Exempting Circumstances).

Insanity: To be exempt from criminal liability, the accused must have been completely deprived of intelligence or freedom of will at the precise moment of the assault.
Effect: They are exempt from criminal penalty but are still civilly liable (damages) and may be ordered by the court to be confined in a psychiatric facility.

5. Trial and Judgment

Once the case reaches the Regional Trial Court (RTC) or Metropolitan Trial Court (MeTC):

Arraignment: The accused enters a plea. If the accused is mentally unfit to stand trial, the proceedings are suspended until they regain sanity.
Pre-Trial: Marking of evidence and stipulation of facts.
Trial: Presentation of witnesses. The prosecution must prove guilt beyond reasonable doubt.
Promulgation of Judgment: The judge issues a decision on the criminal penalty and civil indemnification.

6. Relevant Laws for Reference

Law	Significance
R.A. 7277	Magna Carta for PWDs; ensures legal assistance for disabled persons.
R.A. 11036	Mental Health Act; protects the rights of persons utilizing mental health services.
A.M. No. 00-4-07-SC	Rules on Examination of Child Witness (applied by analogy to vulnerable adults).
Revised Penal Code	The primary basis for defining and punishing physical injuries.