My friend was killed recently fighting in Syria.

Answer

The war in Syria currently is not a valid Jihaad in our opinion. Whether those slain in this war are Shaheed or not, Allah knows best. Whilst we make dua that Allah Ta'ala accepts them and bestows to them the rank of shahaadat if they were sincere, and if they died killing kuffaar, not killing Muslims, we cannot say with certitude that they are definitely Shaheed. We hope and make dua that your friend has attained the rank of Shahaadat.