Using Hints
You'll only be given four hints for each area, so use them sparingly and only when absolutely necessary. A good trick is to wait until you've found all objects except for four of them; you can then use your four clues to uncover the remaining objects easily. Also, remember that you can use your hints on the crime lab computer as well.
Finding the Battery
Finding the battery in "Mystery Case Files: Prime Suspects" can be extremely difficult, partly because it is in a different location every time. Once you've found all of the clues in a given area and you are prompted to select a new area, take a look around the edge of your screen before continuing. If the battery is in that room, you'll easily be able to see it shining against the darkened background. Revisit the area to click the battery and add it to your inventory.
General Tips
If it is taking too long to find all of the clues in one particular area, try leaving and going to a new area to do some searching for a while. Switching back and forth between areas is a good way to avoid unnecessary eye strain and frustration when playing "Mystery Case Files: Prime Suspects." Finally, remember that you'll find colored clues almost always near the same or similarly colored objects in an attempt to camouflage them even further.
Grouped Items
Some hidden items in "Mystery Case Files: Prime Suspects" are presented to you in groups; of course you'll need to find every item in the group to collect every item in every area. Avoid using your hints on these grouped items, as a hint will only reveal one item at a time. This means you'll still be left searching on your own for the remaining items. Also, some players may find it easier to search for all of the grouped items last, since they typically take the longest to find.