Sikh's have always been against Islam and their hatred has increased since 1947 when the Hindu's got India, the Muslim's Pakistan where as they were left empty handed, they're bitter about being the only religious community that does not have it's own country as Khalistan went up in smoke(clap). From their perspective it's okay for Sikh men to date and marry Muslim ladies but they hate it when the shoe is on the other foot.
I am not justifying any criminal activity but every day millions of offences take place in the USA and Europe like theft, car robberies and all where the faith of those convicted is never questioned so why Islam when the fella was probably just a nominal Muslim.
You can't ever compel any heart to believe in any religion which is why i totally dismiss this theory of "forced conversion". Sikh men are unattractive with those smelly turbans and uncut/untrimmed hair which is why many of them today are removing them then being labelled as apostates by their own community. Most Sikh women prefer non-Sikh particulary Hindu and Muslim men due to their neater appearance, it's as simple as that!
It's common for Sikh's to blame others for their own problems like this kid who cut his own hair then claimed that he was attacked.
http://news.bbc.co.uk/1/hi/scotland/edinburgh_and_east/6207509.stm