Plenty of things! Here are a few ideas to help you get started:
Screen your tenants:
When screening rental applicants, do a review of the person(s) rental history to check for prior evictions, as well as do a credit check. The National Tenant Network, which has an office in Tewksbury, performs these services for a small fee. NTN also does Criminal Background checks if you want to take it a step further. The Fair Credit Reporting Act requires you to obtain the applicants permission to run a credit report. Permission is needed to run a Criminal Background Check as well.
Follow the law when it comes to things like screening applicants, taking a security deposit, fair housing laws, building and state sanitary codes, and local zoning laws. The professional tenant will beat you every time if you don’t!
Maintain your property!
A well maintained building sends the message that you are a serious landlord!
Be proactive in maintaining your property. Don’t wait until things get worse. Make it a point to inspect the inside of your units on a regular basis.
Secure all common areas like the laundry and storage rooms, pool area,etc. Criminals like to conduct business in these places.
Keep bushes and trees around windows well trimmed: This will prevent people hiding in them. Consider using fencing that is difficult to climb over.
Post the address clearly on the side of the building: If someone ever needs to report a crime or fire, then they will know the address! In addition, the Massachusetts State Sanitary Code requires you post the address in a location that is visible from the street (Section 410.484).
For all properties that are not owner occupied, the Massachusetts State Sanitary Code also requires you to put the owners contact information and the contact number of the property manager if you use one on the outside of the building(Section 410.481).
Use lighting to its best advantage: Let’s face it; criminals do not want to be seen. Use photosensitive lighting over all entrances, and make sure all common areas are properly lighted.
Control traffic flow: People involved with drug activity prefer areas with multiples exits either by car or on foot. This allows them to escape if the police show up. Consider adding fencing or blocking car exits to control the flow in and off your property.
Warning signs of drug and other criminal activity
High amounts of traffic, especially late at night, where people stop in briefly, and then leave.
Windows in the rental unit have been blackened out; extra deadbolts and locks have been added without landlord’s permission.
“Lookouts” hanging out on the street constantly, and disappearing when the police show up.
Electrical systems have been tampered with to by-pass meters, and/or usage to common area meters has dramatically increased.
The smell of ammonia and other chemical agents permeate the property. This may be a sign that the property is being used as a “cooking” lab.
People carrying items into the property and leaving empty handed on a regular basis.

howard mcgowan
10:50 pm on Monday, April 30, 2012
We have a lot of problens being created by "absentee landlords" excess in rent proposals and lack of consideration for long term tenants,lack of contact etc.
Don
7:30 am on Tuesday, May 1, 2012
Might be the landlords who are absentees, but really folks. How many people in Malden are criminals, know criminals, want to be criminals or are friends with criminals? This is the real problem. When they have no place to go, it is the streets or the welfare system. How can this be fixed? Good luck Mr. Mayor.
mats
11:12 pm on Tuesday, May 1, 2012
So...it appears I am not alone - it can't or won't be fixed, the only option I see is to sell, but now that crime maps are out there for all to see our homes will be worth less than before - Here's a tip for landlords - rent to decent people who care about their living environment even if it means the rent will be less than that guaranteed check in the mail - trust me, the neighbors will appreciate your thoughtfulness
Bobby James
8:20 am on Wednesday, May 2, 2012
You do realize that the crime maps are simply generated off of the public record, right? Police logs have been public record for decades and have been published in the local paper just as long. Just because there's a map online doesn't mean it's that much more accessible.