A man is due in court on Friday charged with the murder of Colin Horner in Bangor earlier this year.
Mr Horner, who was 35, was shot dead in a supermarket car park in front of his young son on 28 May 2017.
A 34-year-old man was arrested in the Newtownards area on Wednesday as part of the police investigation.
He has been charged with murder and also faces a charge of possession of a firearm with intent to endanger life.
The accused is due before Newtownards Magistrates.