Responsibility for family violence lies with abusers, but the power to end abuse lies with all of us. When we suspect abuse, but tolerate it as "none of our business", our silence - as neighbours, friends or relatives - disempowers victims.

If someone has unexplained injuries, appears withdrawn, anxious, upset or angry, or avoids friends and family and becomes difficult to contact, it is reasonable to ask if these are symptoms of physical or emotional abuse.

Victims themselves may not seek help due to fear, helplessness and fatalism, or a lack of access to information or opportunity, especially if they are controlled by the perpetrator. We can help provide the support they need to protect themselves. Knowing that someone cares enough to ask about abuse can make victims feel less isolated. If you think someone is being abused, talk to them in private, but don't push them if they are unwilling to share.

Listen to victims without judgment. Assure them that you believe them and remind them that abuse is never their fault. Discuss available options, including counselling, hotline numbers, family violence specialist centres, family service centres (FSCs), nearby hospitals and police posts, and personal protection orders (PPOs). You can accompany them as they access services.

If they are reluctant to act, accept that decision while remaining available to them. Encourage them to collect evidence in case they change their mind. Photographs of bruises, hospital records and text messages can help build a case.

If you feel the victim is in danger, voice your concern and suggest that they develop a safety plan. Help them pack an emergency bag to keep at your place, list phone numbers they can call, think of safe places they can go to and advise them to keep some money on hand at all times.

It is not advisable to intervene personally with the perpetrator unless it is safe for you and the victim, and the victim wants you to do so. Don't suggest quick solutions without thinking through potential retaliation. It is also dangerous to suggest that a victim should work harder on their relationship with the abuser, or to assume things will get better. Abuse rarely stops without intervention, and might escalate. Couple-counselling in abuse situations can be dangerous. Instead, encourage each party to try separate counselling.

If you suspect domestic violence in the homes of your neighbours, relatives or friends, you can also call the police. Police will investigate bystander reports. Your eyewitness statement can count as evidence.

The police may recommend that the victim apply for a PPO or link them to an FSC. In some cases, they can arrest the perpetrator.

In deciding whether to engage the police, we should put aside our sense that domestic violence is a "private affair", as no one should be left in danger without assistance.

When threats are immediate, the police are the main agency which can respond rapidly and authoritatively to de-escalate the situation and ensure safety.

Yet many rightly sense that police reports may not resolve the longer-term problem. The police do not always take follow-up action. The victim may not wish to see their family member in trouble with the law, especially if they are materially dependent on the abuser. And the perpetrator may well escalate the abuse in the future. For this reason, it is helpful to check in on the victim and offer direct assistance even after making a report as police investigation alone may not resolve the situation.

The state can also help improve the effectiveness of police response by taking a more consistently supportive approach. Negative experiences with police insensitivity can discourage victims and bystanders from reporting.

I once reported a case involving a death threat and evidence that the perpetrator had caused the victim to bleed. In the investigation, both parties denied the abuse. The police officer later told me off for "interfering in their business".

This may reflect the officer's misunderstanding of domestic violence situations and why victims might resist intervention. Regular, victim-oriented specialist training for all responding officers can help police respond in a more constructive way.

Victims might also feel more comfortable if social workers were present during police interviews.

More broadly speaking, questions of social support for older people and children, and material support for victims of spousal violence, need to be resolved on a societal level, so that victims are in a position to make the right choices for themselves.

We have worked with victims who endured abusive relationships for years primarily because they had no alternative housing, means of livelihood or support systems from their community.

Domestic or elder abuse is for all of us to solve. No one should have to sacrifice their well-being to maintain "family privacy".

• The writer is the campaign manager for the We Can!, a community-based movement initiated by Aware to end gender-based violence in Singapore.