The ex-con sought in the slaying of the brother of San Francisco 49ers quarterback C.J. Beathard and another man outside a Tennessee bar has been nabbed, police said Wednesday.

“BREAKING: Accused double murderer Michael D. Mosley just arrested in Cheatham County. Mosley will be booked later today on 2 counts of criminal homicide and 1 count of attempted criminal homicide for Saturday morning’s stabbing of 3 men, 2 fatally,” the Metro Nashville Police Department tweeted around 4:45 p.m.

The cops added that Mosley “surrendered from a vacant home on Petway Rd in Cheatham County after it was surrounded by law enforcement. He was there alone.”

The police tweets included photos of a cuffed Mosley, 23, wearing a gray sleeveless t-shirt, basketball shorts and socks being escorted into an armored police car.

Beathard’s brother, Clayton — the 22-year-old quarterback for Long Island University — and 21-year-old pal Paul Trapeni were stabbed to death trying to help a female friend fend off unwanted advances from Mosley, cops said.

The Beathard siblings also have another brother, country music sibling Tucker Beathard. Their father is country songwriter Casey Beathard.

Nashville police said Monday that they were looking for Mosley.

He has a long rap sheet, including for burglary, assault and drug-related arrests and convictions, authorities said.